The IS-2 was far from on par with the German cats though. It had siginifcant problems with reload time and adjusting the barrel. In WW2 tank engagements the gun would be slightly adjusted after the first miss. That was however a huge problem for the IS-2 since the barrel had to be put into the neutral position to be reloaded and then readjusted to fire again. That lead to quite a slow rate of fire and low accuracy. The thing was built to break through defenses, not fight tanks. But hey, big gun. Must be good.
As for gameplay and balance: Why would it perform better than the Tiger if both vehicles cost the same?
Why does Tiger preform way better than IS-2 currently, if they both cost the same?
And by the way, I said that is should do more damage per shot and BE MORE COSTY while having lower rate of fire. Why don't you just read my initial post?