I've used it before but I just don't play PC games enough besides WoW. If enough people joined in I'd give it a try from time to time I suppose.
Though I did just create my own private WoW server so I can pwn any instance all by my lonesome instead of spending a year trying and thought about inviting others to join it. Kinda cool to just say hey I wish I was dual wielding Illidan's swords, type ".additem" and bam I've got'em. Though making myself powerful enough to one hit him seemed kinda less than I hoped for in the end. :)