With the weapons files from coh2 tools.
I wouldn't call it "utterly useless" especially since we are not talking about two separate vehicles but about exactly the same vehicle pre and post patched.
This is of course theoretical analysis and I doubt that x147% increase in DPS is accurate.
The value thou is simply too high to be completely off by more 50% and the SU-85 being actually worse vs medium now than it was before.
Imo it is safe to say that with increase in accuracy, penetration, rotation and target size the SU-85 perform superior vs PZIV even if its ROF has been reduced.
In game one can see that FF with notorious long ROF is an effective TD because it delivers damage consistently with its over the top accuracy.
Why do you post them then implying that they are a good way of comparing units if you already know that they are heavily inaccurate at best? You are just misleading people with these numbers that might not have the in gamr knowledge of how everything behind the scenes works.
Fact is, TTK is the only real factor that matters, because in tank fight there is no difference between 161 and 320 HP. Your DPS calculation solely based on accuracy overestimates the performance of high accuracy units A LOT. That's like the reason why the 'new' SU85 looks so much better on paper.
Even if we assume that the new SU85 hits every shot and that the old SU85 misses once which would simulate farther ranges (again, this whole setup favors the new version by default), the TTK against mediums would both be at 17 seconds.
It is everything else than safe to say the unit now performs better, because its ROF got reduced by a third.
I woulf really recommend (if you have the time obviously) to check it out in cheatmode, best case with a 0 accuracy mod. I never tested all of this systematically, but from what I have seen in a (rather few) tests I started to count half of the missed shots as scatter hits as a rule of thumb. But again, without real testing. So I'd recommend doing that for the P4/SU85 setup