Try using a JP4 vs IS-2 and SU-85 vs a KT and and come back with th4e results.
The results are quite good. You get to farm vet (vet 5 jagdpanzer is a monster) and alongside a couple raketens you can keep the IS2/KV2/KV8/KV1 on constant repair. Jagdpanzer does a marvellous job vs mediums as well. It’s a great choice for late game AT and couple nicely with a Konigstiger.
I don’t care about comparisons in a vacuum, the SU85 and Jagdpanzer IV are very similar units, tho I prefer the Jagdpanzer for its rate of fire, armour, target size and camo at vet 5.