My D3 has dealt me nothing but minor annoyances. I've experienced occasional lag when launching apps or switching orientation, but that's nothing. I roll my eyes when people complain about those things.
There is a slight blue tint to pictures, but only a slight one. I didn't even notice until I read about it in forums. I had a Moto q9m years ago and those pictures came out looking red and "warm." My D3's pictures come out slightly blue and "cool," but the Moto q9m's issue was much more apparent. I usually take pictures with CamScanner, anyway, as that app enhances fine details, such as background lettering.
I can't speak to possible GPS issues because I've never used the GPS. If I want directions, I read a map until I find them. That may sound stubborn or unreasonable, but I trust my ability to read a map more than I trust the ability of a computer to come through for me when it absolutely has to. Basically, if I want it done right, I do it myself. I'm sure GPS can come in handy sometimes, but I've never needed it.
No random reboots yet in the month I've had the phone. I suppose there's still time, though. I had an EnV Touch that rebooted about once every hour (can't call that random-lol), but a software fix took care of that problem. Honestly, a few random reboots with my D3 wouldn't faze me.
I compare this phone to my D2G and find it to be superior in pretty much every way. Things happen faster and the battery life is better with my D3. I rooted it with the intention of under-clocking my CPU and freezing those pre-installed apps that constantly run in the background (if I need Google Maps, I will unfreeze it), but I only got as far as freezing bloatware. I don't see a point in running Juice Defender or CPU Tuner when my battery is giving me about 12 hours-a-charge (that's using CDMA only, data sync on, SuperDim dialing down my display because that's where most of my battery loss comes from and WiFi turned off). That's not bad for something I use the way I use my laptop.