I played WoW for 4 months right before the lvl cap increase from 60-70. I got to 60 in 3 weeks. I then did endgame (naxx was ok :/), and I got bored of it very quickly. I got bored of the dungeons because I didn't find them challenging and dynamic enough. I never had that problem in FF11 though.

I also didn't like the fact that to play a new class you had to rerole a whole new char.

I would say the biggest reason I didn't like WoW was the community. It was just a completely different mentality from 11. I played FF11 for 4 years and then got bored (mainly cause my closest friends on there were almost all gone). On WoW the guild I was in was nice, but I never really became close friends with any of them like I did on 11.

However, on 14 I'm finding a community pretty similar to 11's. I like the people and the social interactions with them. Despite the low amount of content in the game atm on 14. I havn't gotten bored of it, and I'm already past the time played in WoW.