If the T34/85 gets side armour it wins 3/5.
For the 153124512300112 and one time, there is NO side armor in coh2 and NO medium is able to best panther 1v1, unless it'll start from hitting rear armor and always be there.
With any type of support it should be able to take the panther. Guards buttoning and a rushing t34/85 = a dead panther that probably didn't get a shot off.
While 34/85 is at advantage with support, the question is where is panthers support at this time? PaK40/shrecks>ZiS3/button. Plus, as before, if you are not starting on panthers rear, you won't win.
A T34/85 performs excepionally well considering that it is discounted 25% and has better AI. It also wipes away any other axis armour and it's pretty fast.
T34/85 performs on the level of OKW P4, only difference being, 34/85 uses HP to 'tank' while OKW P4 relies on armor. It does not wipe 'any other axis armor', but it got huge advantage over normal P4. StuG for example will eat it for breakfast.