it is flawed, but as F2P goes, it is pretty damn good.
Lots of events for exp (Pet event, monster killing event, quiz events), decent controls, and faction versus faction fighting.
-Your introduction to PvP will be some level 100+ stomping on your poor level 40 face when you're in town, that level 100+ will have his way with the entire town for a while, you're best bet is to go to another town if this happens.
-Cash shop is insane (your mount confers bonuses to you, without cashshop you can get [iirc] 2, with cashshop 8).
-Leveling is quest grinding (kill 80 of these, go kill 500 of those)
-There was a terrible inbalanced when I was playing (sunwarriors + aoe = win teh game)