KV-5 is a Soviet tier 8 premium heavy tank. I don’t have this tank, so I can’t say anything about its profitability. But according to players feedback it is pretty good. Its main feature is a good «round armor», which means that it has not only good front armor, but also thick side and rear armor.
The tank main weakness is a little turret in front of the tanks hull. This turret has a weak armor, even tier 6 tanks can penetrate it.

Without this weakness this tank would be great. But when developers have added this «hole» in the defense this tank became significantly less popular. На полях сражений встречается всё реже.

Cons – little turret in the front of the hull is a «hole» in the defense. Pros – good round armor.