I used to play it all the time. Not anymore... it has, in my opinion, the best atmosphere and storyline of any MMO out there. Unfortunately it was lacking in the gameplay department.
Too much grind and force grouping to do it. Originally, I played for a bit over a year, and I eventually quit 'cause I realized I was spending too much time looking for a group and sitting around than I was actually playing the game. Whether I tried to start groups, or just ask around for an invite.
Then generally when I FINALLY got an invite, as soon as I got to the spot, I may have been lucky enough for to fight one thing before someone had to leave, and someone else had to go, then we'd sit around waiting for more people, but rarely would they ever come, and even if they did, we'd end up fighting one or two things and another person would have to go.
I still think it was an awesome game, but there was just too much downtime and not enough fun in the end.
Can't wait until FFXIV, though.