Hi
In my opinion nearly all German equipement is a little bit "to strong" in this game.... i.e. 3,7 cm PAK disabling T-34 at 400-500 meters and something like this...
Talking about IS-2 - have a look at it:
http://www.battlefield.ru/is2_2.html
http://www.battlefield.ru/is2_3.html
S!
leon