I actually don't like the curved screen of the Galaxy S line. I'm looking forward for the Note 8 as my next phone. I was going to get an S8+ and after playing with the phone for a while I noticed it felt weird to use apps designed for a flat screen rendering on the bent part of the screen (I actually loved the concept of the first Edge phone that used the edge as a kind of status area).
Regarding the iPhone 8/Pro/whatever-they-call-it, I'll have to wait some time before getting it (June 2018) because I expect it to be around $1,200 and I surely won't expend so much on a phone (I'll get it from my carrier at a lower price included on my plan). So, in the meantime, it will be Galaxy Note all the way until June 2018.