Overall I like the phone alot though I am a bit less enthusiastic than most of you guys.
As others have said, fingerprint sensor is no big deal if you have a case and hold the phone in your left hand anyway. Facial recognition is very fast when it works, but I use readers with my phone most of the time and they throw it off alot. Might try re calibrating. Fingerprint sensor unlocks the phone from the AOD display instantly without touching anything else which is very cool.
Screen is nice, but with the caveat that it's less impressive if you are coming from an S7E. I do like that the overall size of the S8 is noticeably smaller then the S7E but I don't feel the quality is any better. The rolled edges of the S7 are more pronounced and look more impressive but serve little purpose and are a pain some of the time. The S8 seems less prone to inadvertent contact. If I could stand the bigger phone the S8+ would be more impressive visually. Just don't like anything that big in my pocket all the time. No red tint on my screen.
It's nice and fast, no lag, and MOST scrolling is very smooth though my S7E was always fine until a few months of use and loading apps. Chrome in particular is better but still not perfect - don't know why they cant figure that out for such a core app.
I initially found the screen proportions a bit "off" until I loaded Nova Launcher. The default is a 5 across icon which makes the icons a bit small for the narrow screen but 4 looked a bit odd too. Most widgets don't have a 5x1 or 5x2 format so they don't fill the screen right. Nova lets you change the padding and spacing to where it looks much better proportioned. Probably what I am used to and nothing to do with the phone.
The added length is a little helpful on web pages. You can usually see a extra few lines at least when you are reading text. I compared the S7E and the S8 side by side.
Camera is too close to call when you are only taking indoor at night but it's very good. Will try to shoot more tomorrow.
Battery so far is pretty solid, charged to about 95%, 5 hours of use, 3 hours of screen time and a TON up D/L's and configuration/setup changes and I'm still at 60%.
Absolutely love the lack of a physical home button. Though LG and HTC have had this before I can't say how much I prefer it. I've never had a phone whose home button didn't feel sloppy after a year or so. One of my favorite small touches to this phone.
Bixby? - Not sure what to think about it. I'll have to give it more of a chance. Currently it feels the answer to a question nobody is asking. It's way too limiting on the number of apps it works with and I see no value yet but perhaps with time, who knows.
In all I like it and don't think I would return it unless I run into something weird in the next day or two. If you have the resources it's a nice upgrade but if you already have the S7E or even the S6E (I now have all three) you shouldn't feel second class or like you are completely left behind.