Overall, its a decent arcade shooter in MMO format (which is what it is). However, they're unable of using a light hand with the adjustments, and it seems the game swings from mild unbalance, to one side being OP.
But be prepared to buy gold if you want to reach the higer tiers. Without it, tier 8 is about the realistic limit unless you want to do 5-6 matches for every one you play with a tier 9 or 10 tank.