The biggest problem with the game at the moment is the penalty for dying. The rez sickness (called Fear of Death) is a 25% stat decrease that stacks up to 4 times, and lasts 50 minutes at max level (you also get this debuff if you die from PvP). Getting a rez from another player does not remove the debuff either. Neither does logging out, it only counts down while in game.

Of course you can avoid it by buying an in-game item (perfume) for RL money. The cost for each perfume is $0.75US or $13.50US for a pack of 20. Each perfume lasts 30 mins and persists through death, so 20 will give you 10 hours game play with no death penalty.

Otherwise you need to visit a 'servant of light', pay them gold to have it removed, there are usually 2-3 in each zone. However if you die in an instance, you cannot leave the instance to visit a servant of light (if you leave the instance at any time, you are locked out until the following day). You also need to have perfumes if you want to remain competitive in PvP.

So its easy to end up spending more on this 'free' game than you would in a month of WoW.

After having a read through their forums, it seems there are also a lot of complaints about the PvP being quite unbalanced, particularly around the level scaling, and the fact that a player 1 or 2 levels higher can wipe the floor with your toon. Additionally, there are also a lot of complaints about War Banners - basically the servers are PvE, but war banners allow you to force another player's pvp flag on - consequently this has led to a lot of griefing by max level toons in lower level zones.

Cheers,
S.