I'm way too addicted to the S-Pen now to 'go back' to an S model, BUT if it comes out with intriguing features, I just might give it a try. That being said, I'd like an S7 plus... I really like the bigger screen, but I've used an Edge phone before and the 'side' features are gimmicky at best, developer support for those is near to nonexistent, and while a lot of people don't seem to mind, the glare and reflections off the bends at each side just gets in the way for me. Yes, it looks intriguing and a bit sexy, but once you try to look at the screen comfortably, those do get in the way, at least in my opinion. I also found that having a touch-sensitive portion of the screen on the sides caused way too many accidental inputs and actions while simply holding the phone. Plus, a lot easier to get good cases and screen protectors to good ol' flat screens than curved ones.
So, yeah, I'm not a fan of curved screens (TVs either... they just....that's not... looks so... why???!...ughhhh!!! hahaha).