My iPhone 5 heating up was an issue for me on beta 1, reduced significantly on 2. It's probably a bit too early now, but anyone who suffered a lot with this on 2 notice it's gone in 3?
I had the same situation in 1 but fixed both issues by turning off the automatic app updates in the background. Now in 3 my iPhone 5 is heating up again and showing very poor battery life, even after having checked that the automatic app updates was toggled off and restarting.