Since it is a free 15 day pass I do not see why anyone would not give it a go. I really enjoy the game and look forward to returning to it once my schooling dies down. The only drag for me is the end game, but as others have suggested here, all the in between stuff is great and if you are one who does not mind repetition of quests once you get a toon to 50 there are several more story lines to check out.
Plus there are quite a few Guardians playing and the enjoyment factor of any game is increased 10 fold when you play with guildies.
just my two cents.