Coming from Guild Wars this feels fresh and new. If you are a PvE player the lush environments, sweeping music and hours of entertainment will quickly see you hooked. The gear advantage does unbalance PvP a bit when compared to more skill based PvP games like Guild Wars, but the non instanced world PvP option certainly adds to the general dread you feel when wandering into contested or enemy territory.
Criticism is often levelled at the grinding nature of quests, the time consuming walks between zones and so forth and if you are not looking for an immersive experience this game will probably not appeal as much to you. But allowing yourself to be swept along by the World of Warcraft creates a wonderful game that will soon have you longing for more hours behind the keyboard.
The subscription model is one of it's hindrances, but becomes a cost/benefit comparison. Spending $49.95 (See Game Card
here) every two months for what amounts to at least a hundred hours of entertainment seems more than reasonable, but this is a value judgement that every consumer will need to make for themselves.
Overall, if you have the time, patience and funds to play the game I would definately recommend it.