I’m using Gnome and it works surprisingly well. All browsers and Gnome apps look great out of the box (apart from blurry icons occasionally). Qt or WxWidgets-based apps have clipped text and small checkboxes etc; they are usable but it is not pleasant. I use only two of those apps, and I rarely use anything more than a terminal, a browser and a music player, so 90% of the time everything looks great.

I didn’t have to configure anything; Gnome automatically set the scaling factor to 2 and everything worked out of the box, browsers too.