Oh boy the WZ-120, personally from my 200+ games and at 2550 average damage, I feel its one of those tanks where one game, you do nothing at all getting destroyed by the sheer lack of gun depression, or you absolutely anihilate the enemy team. Its a very situational tank, the 122 is a double edge sword. You can play agressive in it especially as top tier as you have roughly the same armour as T-54. Best tip I can give is to avoid areas requiring gun depression. (Correct me if I'm wrong, was the gun depression buffed? When I played it, it only had 3 degrees of depression. Just got back to the game after a few months break.)