ASUS returns with its strongest line of ZenFones in years — including a super-high-end Deluxe model that impresses both inside and out.

The ASUS ZenFone 2 was one of our favorite budget phones of 2015, eventually expanding into a fully-fledged range of handsets across different price points. ASUS has taken its time bringing the ZenFone 2's successor to market, skipping the year's first few tradeshows and launching the ZenFone 3 line at the Computex show in its home city of Taipei.

The third generation of ZenFones kicks off, appropriately, with three new handsets. The vanilla ZenFone 3 picks up where its immediate predecessor left off, with a fine-tuned balance of technology and design in a mid-level handset. The ZenFone 3 Deluxe supercharges things with one of the fastest processors available, the latest camera sensor from Sony, and a beautiful unibody design. And the ZenFone 3 Ultra is a modern-day successor to the FonePad of old — a huge phone with dual-SIM capabilities and a massive battery which can double as a power bank.

We've taken an early look at the new ZenFone 3 devices ahead of today's announcement, spending a scant hour or so with the new range. Read on for our first impressions.

ZenFone 3 series video walkthrough

ZenFone 3

Vanilla Zen

ZenFone 3 first impressions

The regular ZenFone 3 is the lowest-specced of the three, and presumably the most affordable too. In design terms, it's a radical departure from last year's ASUS phones, with the manufacturer almost completely ditching the plastic chassis that characterized the ZenFone 2 line. The ZenFone 3 is all about metal and glass, with a sandwiched design similar to Samsung's recent handsets. Corning Gorilla Glass coats the front and back, with gentle tapered edges that blend into the metal frame. Unlike its larger siblings, the regular ZenFone 3's frame is broken up by antenna lines, and there are noticeable plastic joins around the USB port and where the glass joins the metal.

You're not getting Galaxy S7-class build quality, but you are getting more premium build than many in the entry and mid-level spaces.

This is no Galaxy S7 — but it is a step above what you'd expect from a mid-level phone.

The ZenFone 3's front face is more or less featureless except for the 5.5-inch 1080p IPS+ LCD display, which sits above the capacitive keys for home, back and recent apps. While 1080p at 5.5 inches isn't going to turn any heads, the display is perfectly decent for what's looking like a mid-range phone. It doesn't excel in brightness or vividness, but nor is it offensively bad.

The entire assembly is a comfortable fit in the hand, and the rear-mounted fingerprint scanner was easily reachable for us — though if you have smaller hands you may want to try before you buy. We'll need to spend some more time with the new ZenFones to get a grip with their fingerprint security features, but it's been a while since we've used a really bad Android fingerprint setup, so we're hopeful.

ZenFone 3

ASUS brings an impressive list of camera specs to the table.

Also around the back is ASUS's PixelMaster 3 camera, based on a 16-megapixel Sony IMX298 sensor and backed up by myriad hardware features. First up is the all-important OIS (optical image stabilization — of the 4-axis variety, ASUS says), backed up by electronic image stabilization, dual-LED flash and a new "TriTech" autofocus that combines a laser AF unit, phase detection and contract detection. All that hardware, combined with ASUS' software tweaks, produces a camera that's actually pretty good based on some limited testing time ahead of the phone's announcement.

Running the show is Qualcomm's new Snapdragon 625 processor — an updated entry-level chip with eight ARM Cortex-A53 cores clocked at 1.8GHz, and a new Adreno 506 GPU. The processor's also manufactured using a more efficient 14nm process, meaning the ZenFone 3 should be far more efficient than Snapdragon 615 and 617 devices that came before it. If that's the case, there shouldn't be any need to worry about battery life from the 3,000mAh fixed cell.

USB Type C

Other notables include a USB Type-C port, just like its big brothers, and a new sound system supporting high-definition audio. In the vanilla ZenFone 3 it's paired with a speaker system that's loud enough, though not as impressively bassy as the multimedia-centric ZenFone 3 Ultra.

In recent years ASUS has taken a relatively heavy-handed approach to its smartphone software, and the ZenFone 3 unfortunately continues this trend. The new ZenUI 3.0 — based on Android 6.0 Marshmallow — is heavily customized, with ASUS focusing on an every expanding list of features, seemingly at the expense of overall aesthetics. There's a cartoonish look throughout, with large rounded icons and color schemes that seem haphazardly chosen. It's the sort of smartphone UI you can probably live with, but it's lacking the sharpness of vanilla Android, and the attention to detail that Samsung now shows in its offshoot of Android.

Like the Samsung of 2014, ASUS is still trying to feature its way to success.

One thing ZenUI has in droves, however, is features. There are bundled apps for just about everything imaginable. Want to measure how far away things are with the autofocus laser? A preloaded app is ready and waiting. There's an app for clearing stuff our of memory — like HTC Boost+ — because some people still incorrectly think that improves phone performance.

And ASUS is also promoting a built-in news reader — ZenLife — in some markets, a la HTC BlinkFeed. ASUS is making baby steps forwards in terms of the consistency of ZenUI, but right now it seems stuck in the same rut Samsung occupied a couple of years back, where it wants to feature its way to success. Less, not more, is what the company's software needed in our view.

At least there are plenty of ways to customize ZenUI, including a vast array of third-party themes in the company's Theme Store. And although the look of ZenUI might not match your tastes, performance doesn't seem to be a problem. In our limited time with the phone performance has been buttery smooth, with no signs of lag or animation slowdown. That promising both for future ASUS phones and upcoming devices running Qualcomm's new 625 chip.

ZenFone 3 Deluxe

The Flagship

ZenFone 3 Deluxe

In years past, ASUS has seemingly shied away from directly competing with the bigger names in high-end Android phones in the all-important high-end space. With the ZenFone 3 Deluxe, that's no longer the case. The highest-end and presumably most expensive) of the ZenFone 3 devices leaves nothing on the table when it comes to design or hardware muscle.

You'll need to look really, really hard to find the Deluxe's antenna lines.

On the outside, the Deluxe sports a beautiful aluminum unibody worthy of any top-tier smartphone. Its back is a single curved sheet of metal, unbroken by antenna lines, and that's because ASUS has incorporated them in the outer trim of the phone, as part of it's so-called "invisible antenna lines" technology. If you look really, really closely, you'll see small raised areas around this border where the antennae are housed. The trade-off is that the edges of the phone have a slightly more plasticky feel than the back panel — ASUS insists it's all metal, for what it's worth — but on the flip side you don't have to deal with any unsightly plastic bands top or bottom. (Though you'll still have to deal with camera protrusions, and a recessed area for the rear-mounted fingerprint scanner.)

Around the front, the ZenFone 3 Deluxe is more of an acquired taste, with ASUS "spin lines" metal pattern at the top and bottom, framing the 5.7-inch display, and capacitive buttons down below.

The Deluxe also bumps the screen up to 5.7 inches diagonally, while sticking to a 1080p display resolution. But this time a SuperAMOLED panel is used, allowing for more vivid colors, better power efficiency in certain conditions and ASUS's new always-on display mode. The latter works about the same as similar features from Samsung and LG phones, with a customizable clock widget being displayed at all times, along with a cluster of app icons showing you any pending notifications.

ZenFone 3 Deluxe

How does Snapdragon 820, 6GB of RAM and a quarter-terabyte of storage sound?

There's even more to impress on the inside, with a Snapdragon 820 processor running the show, paired with an enormous 6GB of RAM and up to 256GB of UFS 2.0 storage. That's right, you'll be able to get this phone with a quarter-terabyte of internal memory if you want, and throw in an SD card to augment that. As you'd expect, the Deluxe absolutely screams. And ASUS has built in a suite of gaming options to enhance performance further, while also including built-in streaming support through YouTube and Twitch — similar to Samsung's Game Launcher options on the GS7.

Meanwhile the battery matches the regular ZenFone 3's 3,000mAh, but with Qualcomm QuickCharge 3.0 support built-in for quicker recharges.

The camera, too, gets a sizeable upgrade in the Deluxe. It's still officially an "ASUS PixelMaster 3.0" setup, but this time with a superior 23-megapixel Sony IMX318 sensor — an updated version of the sensor from the Japanese firm's own Xperia Z5. That's backed up by all the imaging tech from the vanilla ZenFone 3 — four-axis OIS, three-axis EIS, "TriTech" autofocus, including laser AF, dual LED flash and a color correction sensor. And although we've only had a limited time with the Deluxe's camera, early results are promising, with fast captures and extremely quick focus times.

The ZenFone 3 Deluxe is probably the most exciting phone ASUS has fielded in years. Inside and out, the manufacturer has packaged an impressive collection of internals into a great-looking metal exterior. And if the price is right, the Deluxe could be a really great unlocked option.

ZenFone 3 Ultra

The Phablet

ZenFone 3 Ultra

As much as we've come to loathe the word "phablet," the ZenFone 3 Ultra is a phone that deserves this cringey monicker. With a colossal 6.8-inch display, this thing really does straddle the line between smartphone and tablet. And with its extra size comes space for an enormous battery — a 4,600mAh cell, with QuickCharge 3.0 support and the ability to reverse-charge back to other devices at up to 1.5A.

In terms of design, the Ultra sits somewhere between the regular ZenFone 3 and the Deluxe, with a metal-bodied design and "invisible" antenna lines, but with a few necessary changes to accommodate its gigantic size. The volume rocker has been moved around the back for easier access when the phone is held in landscape orientation, and the fingerprint scanner now lives below the screen as a clicky Samsung-style home key.

ZenFone 3 Ultra

Half-phone, half-tablet in its purest form.

On the inside, the Ultra runs an octa-core Snapdragon 652 SoC — a solid processor that we've used in rival devices like Sony's Xperia X, and a chip that's more than up to the task of powering Android on a 1080p display. The Ultra also inherits the ZenFone 3 Deluxe's impressive camera setup in its entirety, and we didn't notice any significant slowdown when taking pictures on the Ultra, despite the comparatively weaker CPU.

ASUS is pitching the Ultra as a machine for multimedia junkies as well as road warriors, and as such its built in the same 5-magnet speaker system as the other two ZenFones — more magnets mean more powerful audio, the company says — along with DTS 7.1 support for headphone-based surround sound, and DTS HD for high-res audio playback. Audio playback from the Ultra is certainly powerful enough, though we would've preferred a front-facing speaker setup in a device of this size. With the speakers where they are, on the bottom trim, it's still relatively easy to block them with your palm.

While the Ultra's appeal in Western markets may be limited, this is the sort of phone that'll likely sell in droves in parts of Asia, where big screens, big batteries and dual-SIM capabilities are in high demand. Price, however, will be crucial, and that's one detail we don't have just yet.

MORE: ZenFone 3 versus Deluxe versus Ultra: What's the difference?

A promising start

The Bottom Line — for now

The biggest difference in the ZenFone 3 series compares to last year's ASUS lineup is focus. The ZenFone 2 series always seemed a little haphazard, with myriad near-identical products thrown into the mix. This year's ZenFone 3 line kicks off with three clearly differentiated products — the regular ZenFone for budget-conscious buyers, the Deluxe for spec junkies and the Ultra for buyers seeking a decent, small connected tablet that also doubles as a highly capable smartphone.

ZenFone 3 Deluxe

All three devices look promising on the hardware side, and we're particularly impressed by the Deluxe, with its beefy specs and impressive metal unibody. Software is still an area of weakness for ASUS though — the new ZenUI remains way too busy for our liking, despite its quick performance.

But a huge part of the ZenFone 2's success was its attractive price point, and it remains to be seen whether ASUS can offer a similarly affordable lineup in 2016, while also bringing significant improvements in build quality and internals. (With ASUS now fielding Qualcomm processors across the entire line, it'll no longer benefit from the purported subsidies offered by Intel to phone makers using its Atom chips.)

Nevertheless, it's a promising start, and we're looking forward to spending more time with all three ZenFone 3 devices in the near future.

Do you you own an earlier ASUS ZenFone device? Would you upgrade to a ZenFone 3? Share your thoughts down in the comments!