I enjoyed it alot at first, got bored with it about a week later, then right when I was about to give up I met some cool people to hang out with in the game. So IMO unless you can get into the "social" aspect of the game there isn't much there.
Well, there IS a good reason for games to be rated 'M'. Unless it's something like a nipple being shown from some Japanese import that's otherwise quite family-friendly... Personally, I think they should card people who want to buy/rent 'M' games.