I've been playing this game for the last couple of weeks. It's still in open beta, but it plays and feels very nice. I like the idea of dual classing. Even though you have to level each class separately, you get certain bonuses on your main class from your secondary class. So if you're a Warrior/Rogue, you'd get the dual wield ability from the rogue on your Warrior class (along with some more abilities). So it really pays to take up that second class. other then that, the game developers have taken a good look at what works well in other MMOs and have implemented it into this one.

I haven't done any instances yet, so I can't talk about that yet. I'll let you know when I have.