Bought a second-hand S8 last week. It was opened from Jan-2018 and I rebought from the owner. My first feeling is it's very beautiful with color black mid-night.
My old phone is S6e+, bigger than this S8 but I feel ok after 1 days used. Battery is always the problem but when I turned off AOD, replace Facebook and Messenger original apps with Lite fb and messeger, the problem is solved. Now I can go out without a charger battery ( wake up 7 a.m and come home at 7 p.m - web, fb, mess,... not whole day but sometimes)
It's a little heavier than my S6e+ so I think the material qualification of S8 is higher also.
I'm not using screen protector nor any case because I think its the most beautiful phone without all of this.
P/s: Sorry my English is so terrible but sure that all of you can understand xD