I've had mine for over four months now and...
Starting with the hardware, the screen more specifically. It's Gorilla Glass, yet somehow, I've managed to scratch the screen.
I've never scratched any of my phones and this is no exception. Compared to the Nexus 4/5 it shows fingerprints like a pig, but I can wipe.
I never use screen protectors on phones, I don't like the tactile feedback from them.
I don't like the *sparkle* ground glass effect they have. What's the point of a high-rez screen if you're going to put low-rez whatnot over it?
The GPS is slow to track many times.
Of all your complaints, this is the one that occasionally happens. Sometimes I get a lock in <5 secs; other times it can take 90-120 secs and a reboot on top of that. Once it's working, it's solid; but it can get flaky. It was much worse before the last update.
Let's talk about the software, oh the software. The software on this phone is horrendous. It's absolutely positively filled with bugs.
No. Just...no. I can count on one hand the times it's randomly appeared to have rebooted, but that has happened with every phone I've had. All of them. Other than the rarely occurring video tearing effect that's being fixed in the next update, it's been as good as anything before it.
The absolute BIGGEST problem I've seen so far is something that many OPO users are experiencing. The phone will NOT make a phone call when connected to an LTE network and not WiFi.
I've never had this happen. Never. NEH. VER. I've never dropped a call other than when I've walked too far into my work building which is like a Faraday cage for 85% of the site.
It sounds like you have a defective unit. The OPO isn't a bad phone. Since Google blew it with the Nexus 6's price, I'm set until something cool happens in 2015.