I'm fine with having some bugs on a new phone as long as they get fixed. What always worries me is things like overheating or terrible battery life that just can't be fixed. My last experience with the first one was with the Sony Z5 Compact because the touchscreen felt just a little bit hot at all times, enough to feel uncomfortable. With my Oneplus One I get none of that and I hope the same is true with the Note 7. I understand that the phone will get hot when you initially restore from a backup but that is fine as it is not the norm.
Manufacturers insisting on the metal backs is not necessarily a good idea. While it surely helps dissipate heat, I'd rather not feel the heat from the phone when I use it.
Your Z5 Compact was the victim of the Snapdragon 810 which had major heat issues, many Samsung avoided it, the never was a S810 based Samsung and LG went with the 808, like Samsung, the never was a S810 based LG. Very unfortunate situation for Qualcomm there.
I think with these newer IP67/68 certified devices, all that heavy sealing also contributes to more heat being trapped, and also what doesn't help is these devices getting slimmer meaning components getting closer to each other and less room inside the devices.
I think Polycarbonate was a great material to stick to for smartphones, it handled heat far better and it was much better at absorbing the force of a bad drop. All this metal and glass is just not working.