KV-1 is not worth the cost to be honest, its main gun is terrible. The only purpose of building this tank is to soak up damage (I would rather build KV-8 for this role). I think the coaxel machine gun needs a bit buff to damage infantry if the tank is useless against tanks.
The KV-1 will has a very good chance to beat a PvIV so its in not useless against tanks.