So, here's my thoughts. I'm going to mix in Lollipop thoughts here too.
- The phone is wide. I can see why Apple has been reluctant to make the iPhone wider up until recently. I have giant hands, and this is really pushing the limits of comfortable grip.
- Screen brightness "issue" seems overblown, but I am not overly picky about this and prefer my screens dimmer than most. I have kept Adaptive Brightness on, and I'm content with how the screen adjusts itself indoors and out. YMMV.
- As you'd expect, rendering of fonts and such looks great at this resolution.
- As of right now, I'm not too impressed with battery life. As I've hinted at in this thread, I'm a demanding user that typically has a lot of SOT in a given 8 hour work day. I reserve my final opinion on this, though, until we see more updates.
- Things I miss from iOS - Lightning connector that plugs either way, the way Siri will take and read text messages for me over voice (I need to find a good app to replicate this functionality). It's nice to have MightyText back, though.
- Variety of "smart lock" options is truly nice to have. I thought I was going to miss TouchID, but having stuff like auto-unlock via Bluetooth has largely made that a non-issue.
- While the speakers sound great playing music or videos, phone calls sound pretty iffy quality-wise, on speakerphone or otherwise. I'm wondering if there will be fixes here, seems much worse than it should be, even given the quality of cell voice.
- Have not hacked in the encryption disable, performance seems fast enough that I haven't bothered. I think this is going to turn out being something that only bothers people if they see an A->B comparison.
Overall, despite the nitpicks, I'm pleased. I'll be curious to see what kind of improvements software updates bring, but right now I think the phone is at a good starting point.