As a KV-5 owner, it's only good with aligned stars and heaps of know-how.
When you know how to utilize the beast correctly: You will annihilate anything with weak spots or poor armor due to the RoF of your 107mm.
If you get unlucky, frisky or do something wrong: You get fucking wrecked due to maneuvering like a shit bucket and having 1/4th of your frontal profile being a weak spot.
To be honest, I enjoy it more than my Lowe. Faster, better damage-per-minute (if you can pen) and it makes a hilarious rammer. Not saying the Lowe is bad, but mine is just cursed with the absolute worst teams.
The KV-5 at least can enjoy the hilarity of 400-700 damage rams, and killing a tracked scout or AMX 13 series outright.