I've been to Disney with friends 3 times. It depends on the friend really. If the friend is picky about rides and food it might be a tough time. But overall I can't recommend it enough it's great.
and I went twice with parents and once without. Splitting off from them is much easier and more fun for both parties. Parents get to do the boring stuff they like and kids get to do the fun stuff.
Also you got a wingman/girl if you're lookin to pick up somebody at the hot tubs at the hotel. haha.