Great fun that's definitely worth the wait and every penny.
The only downsides to this game is the slightly buggy launch (although most of the bugs seem to have been fixed) and a class balance which isn't exactly up to par. Harder classes, like the elemntalist, thief and mesmer don't reward a player for taking the long time it takes to master their class over easy, pick-up-and-play classes like the ranger, guardian and warrior, who have forgiving armor, healing and plenty of ways to save themselves from a bad situation with minimal effort.
The game also doesn't make you read through text in order to understand the game, rather it forces you to learn skills as the game gets harder (eventually, even heavy armor classes will have to dodge in order to avoid damage.) The difficulty ramp feels just right for most classes, but playing a class like a mesmer will definitely give you a challenge and force you to use tactics to solve a situation while a class like a warrior will let you charge into most situation and think as you go.
Overall a solid 9.5 out of 10. Once balancing and a few minor bugs have been fixed then it would be a definite 10 for sure, but 0.5 off for now.