It does so many useful things for YouTube's interface that you almost kind of forget it's there, which features are YouTube's own and which are *Enhanced* ! :-) It's a little like Reddit Enhancement Suite in that respect. These settings I'm currently using (there are more): mousewheel volume control, pinned video when scrolling (only when configured to appear top-right so it doesn't obscure either the comments or the suggested videos you're scrolling towards--otherwise it's better off IMHO), ad removal, automatic pausing, auto expanding descriptions and most happy with the option for disabling the autoplay feature! (the last one feels like one of the many instances of Google using shitty default settings to passive aggressively annoy people that like to clear their cookies on exit). Oh and I just discovered the dark theme, giving it a test-run now, but it looks nice and calmer to the eyes. And I'm curious what sort of fun things I can make with the custom script feature :D