We've written a few tips here for those who are new to Android with their BlackBerry Priv, but this one is for the Android users who just picked one up, and aren't familiar with all things BlackBerry — when you insert a SIM card into your unlocked Priv, some things will change.
Before you light the torches and sharpen any pitchforks, the changes are only cosmetic, and are easy to undo. And in some cases, you'll be glad they changed in the first place.
Your phone is still unlocked, and you'll still be free of any real carrier branding.
When your Priv — or any modern BlackBerry that's factory unlocked — first connects to a carrier's network it configures itself for best performance. That's the stuff it's doing while you sit there looking at the signal indicator bars, waiting for them to light up. Most phones do the same thing. What BlackBerry does in addition to network optimization is copy a new splash screen to your boot up process, and change the ringtone to the carrier's default. For example, I set up my Priv with no SIM in it. After everything was done, I dropped in my T-Mobile (US) SIM card. I was prompted to reboot, and when I did I noticed the T-Mobile splash screen, and when all was said and done I was automatically connected to Wifi calling and HD voice was enabled without me doing anything. My ringtone was also changed to the familiar, but annoying, T-Jingle thingy.
There are logos, wallpapers, splash screens, boot animations and ringtones stored in the Vendor folder in the Priv's system files. You're not downloading anything, and the system just changes which files the default settings are linked to. Other than a change in your boot animation, you can change everything back through the normal methods.
One other thing we noticed on Richard's unlocked Priv, was that an O2 SIM also triggered some suggested applications to install from Google Play. I didn't see this behavior with T-Mobile US, but in either case don't be alarmed if you see something similar. If you like what is suggested, install it. If not, ignore it. Your phone is still unlocked, and you'll still be free of any real carrier branding.