I have been playing ff for a year (today!)
I just recently starting playing WoW with the BF. (i know, but i'm not a traitor i promise)
I like the graphics of wow, because some of the places are really pretty, but it's insanely easy. I'm used to losing XP because I F up.. but it's like there is no true reward system with WoW. You die, no xp lost, no bloodwarping, no test. There is not much of a big challenge, except for getting out of aggro range.
I like it, but FF will always be my full time MMO :)