I played Aion during the last two betas and got to level 20. Regardless of that, I wasn't very fond of the game. I found that the graphics and whatnot were great, but I found the gameplay to lack things I like about other games.

One thing is the zoom, incredibly small zoom range annoys the hell out of me in a game, besides a first person shooter.
When fighting with monsters the same level, the character was always running pretty low on HP, besides if you were a cleric really.
The characters themselves, move really, really, slow. Which makes traveling a hassle unless I wanted to pay a fee to fly to someplace fast.
The flying itself, was annoying. Limited flying time? Why? And if you fall from a high height or are flying in the air high and fall, you get hurt big time. Not that it isn't realistic, but it's annoying.
I found the 3D moving style reminding me of the first Resident Evil back on the PlayStation. I really did not like the way they handled the motion.
The mini map was annoying as hell, as well. Basically, you had to make your character spin in a circle to see the aggro monsters and non-aggro monsters around you. Isn't that nice? Because it will only show the ones in a cone-esque shape ahead of you, as well as the ones right next to you, which I really would have liked to have known before I walked backwards into them.

Overall, I was incredibly disappointed in the game. Graphics aren't everything if the gameplay sucks. Well, that's my two cents.