Sorry for the late reply, I had knocked out a while after posting

No camera button bothers me a little, but I can have it on the action center, so that resolves that.
What does proximity and ambient light sensor do? Is that the automatic brightness?
The nav buttons is my favorite thing, I hope they actually respond unlike on my 521 (which probably happens because I'm running Dev Preview, so it makes sense.
Wifi Calling problems, you guys have that too?! I thought it was just me because it would stay on even after theres no more wifi.
Finally, is LTE better than 4G? On the Nokia website I see it only has 3G, not sure if it makes a difference besides bragging rights.
Edit that I forgot: I doubt the news phones and OS are coming to metro, maybe to t-mobile, and then I'll be able to use it on metro, but probably not straight to metro pcs :/