I can honestly say I'm quite addicted to WoT. Been playing since before Xmas and I have a KV-3, PzKpfw II Luchs (Elite), Stugg III (Elite) and a JagdPz IV.
Being able to use free gold for premium account benefits really makes a difference so I'm tentatively waiting to see what the costs are at launch. It can be a real grind when you first get a new tank because the basic loadout is usually not enough to damage anything in the battles it puts you in. It's most frustrating knowing that you might aswell be throwing spit-wads at that IS-3 bearing down on you.
The matching system can be a bit off the mark, often you'll get put in a battle where you can literally be one-shotted by everything on the other side, and others you get put in one where you can one-shot everything on the enemy team.
Great game to just pick up for half an hour for a few matches and put down again. Although that, "just one more battle" factor is very hard to resist!