It does a lot of things, though many are somewhat subtle, like screen locking timeout and stuff with networking and a bunch of utility programs and so on. I like to start off Xfce Debian and plaster i3wm over it, it's the best 'power user' setup I've come across.

I wouldn't hesitate to put a 'regular' computer user in front of Xfce, it strikes a nice combination of simple and discoverable with very few annoyances. It's also where I go when I want to use some many-windowed application that doesn't fit into tiling.