The KV series performed quite well, as did the later IS tanks. The only WAllies heavy that was truly worthwhile, in my opinion, was the Churchill tank. Even then, that was mainly because of the Funnies rather than it being a good tank. Hope this helps.
I once made the mistake of suggesting that the Churchill wasn't much good and was unreliable (well the internets says so - so it must be true) within hearing range of a WW2 Churchill tank veteren (North Africa and Italy) and oh boy oh boy did he put me right.
If you were to ask a Churchill crewman what advantages a Panther tank has over his Churchill the response will be - the panther has a slightly better gun and is faster on a road - without any irony - they trusted their tanks.
Fact is that the Churchill could go pretty much were a goat could go where other tanks could not.
Its cross country mobility, and hill climbing ability was unrivaled - perhaps matched only by the Cent when it finally arrived.
It also had a reputation for saving its crews when hit and not burning. (note all tanks burn eventually)
I would say that the Matilda II in North and West Africa was to the Italians what the Tiger would later be to the Allies.
So relatively it was a Heavy tank as far as usage and its peers of the day is concerned
Also as it was more reliable than the Cruisers of the day it generally developed into a 'universal tank' and it came as a great shock when they started getting knocked out by long 50s later in the North African Campaign.
Also just look at it - it looks like its been chiseled out of a chunk of unobtainium
I just looked on the interwebs for a nice picture of it and there is a number of pictures showing knocked out Matilda II but none of them seem to have burned!