Two Buttons

You might of think that the is2 and kv2 are of so good,the is2 actually is a good design.however the kv2 had a tendency to fall over due to recoil if its turret is facing left or right.not only that,it was heavy,and the high boxy turret made it vulnerable.

For one I know the IS-2 incorporated more armor, a better-performing gun, a better mobility and a better overall stats than the KV-2.
Second of all I know both these tanks and big they are as I have seen them in Russian museum, I bet you are just an internet fanboi.