The best Android phone is more than just the sum of its parts.
There is some really good, and interesting, stuff out there in 2015. We've moved past the gimmicks like 3D and dual-camera lenses, and the folks who make Android phones have worked hard to deliver something for everyone.
But after all the dust settles, the Nexus 6 is the best Android "flagship" you can buy, even though it's not the newest.
Granted, the Nexus 6 doesn't have the best screen. I'm pretty impressed by what I've seen on the Galaxy S6 and the LG G4. But I've never looked at the screen on my Nexus 6 and said, "this is horrible." That's because it isn't. It's big, bright, and 493 pixels per inch are enough to make anything look great on the 6-inch display.
The Nexus 6 also doesn't have the best camera of any phone available. The LG G4 is the first Android phone with a camera that's more than good enough, and if your main reason for wanting an Android smartphone is the camera, you should probably think about buying one.
There are also plenty of folks, like me, who just don't love carrying around a 6-inch phone. I can use it just fine (save the cracks about my lack of manly hands), but I don't like the size of it in my pocket and it doesn't fit in the cup holder of my car very well. I've come to terms with it, because just about every other Android phone is bigger than I like, so I have to suck it up. I'm looking forward to the next Z-series compact from Sony, though.
There are plenty of things about the Nexus 6 that are done better by the competition, so why in the heck do I say the Nexus 6 is the best phone you can buy?
I'll be up front — I'm a software guy. Take a room full of smart engineers and they can design a phone that ticks all the boxes and is the best thing ever — on paper. When you pick it up and use it, you soon find that the software is like the soul of a phone, and makes all the difference.
I don't mean TouchWiz versus HTC Sense versus "Stock" Android versus whatever LG calls its stuff now. It's perfectly fine to like a thing that looks different from another thing. I mean the way the software works, how well it works, and how good the next version is going to work.
Software is like the soul of a phone, and makes all the difference
The Nexus 6, like every other Nexus phone before it, had a rough few months in the beginning. I joke and say Nexus users are Google's beta testers, but it really does feel that way when a new Nexus phone comes out and we're trying a new version of the operating system. But, also like every Nexus phone before it, Google pushes out updates that address the complaints we all find. Right now, Android 5.1.1 on the Nexus 6 is the best version of Android ever. Even more telling, Android 5.1.1 on the Nexus 5 runs better than every other 2015 phone, too.
This is because one company is in control of both the hardware and the software. The Galaxy S6 is a technological wonder. You can't help but be impressed with the design and the hardware used to make it all happen. But on the software side, they have to use a product designed by another company with another phone used as the initial software target. They wait on Google to make changes, alter things to try and optimize the software for their gear, then build a different user interface on top of it all. They find ways to make it better and send the changes back to Google, and the next version of Android will probably run better on their phones.
In the meantime, you have issues stemming from using an older version of Android, as well as issues Samsung introduced itself. The same goes for LG, and HTC, and everyone else building Android phones. Software is hard. Getting it right takes time and dedication. Getting it right while also trying to change the entire interface means it's never going to be as smooth as the original. An interesting aside — when HTC monkeys with the RAM management on their phones, we call for their head. When Samsung does it, we blame Lollipop. This says more about us than the phones themselves, though.
The Nexus 6 isn't perfect. Nothing ever is, really. But if you want to spend a bunch of money on an Android phone, it's the best way you can spend it.