I just pre-ordered the One S, and it's gonna be a huge upgrade from my Samsung Galaxy Gio! I read nothing but good things about this phone. The screen is big, but not too big although it will take some getting used to as my Gio has a 3.2 inch display.
I have seen a display comparison video from PocketNow (can't link it yet since I'm new here..) and as far as I can tell the One S beats all the other phones, including the iPhone 4s and the SGS2 in terms of design and display quality. Of course filming screens is not the best way to compare, yet it definitely holds it's own according to the reviewer as well.
By the way, does anyone know how the 25G free Dopbox space works when you already have an account?