Isnt that exactly the kind of problem the unit has? It doesnt have a clear role.
Its not good enough against infantry compared to a medium /heavy AND doenst have the abilities to (reload times, urrrggh)fight effectively against Jacksons / SU-85.
Yes, the panther has good mobility which can be used against SU-85 (but only on maps that allow flanking) but the Jackson has more range AND the same mobility AND costs 40 fuel less.
The bigger problem is that axis players need tanks to fight off allied infantry. The panther doesnt give you anything in this department but is very expensive. Building 1-2 mediums and back it up with a Tiger is a lot more attractive than spending my fuel on panthers. Thats why OKW players choose so often Grand offensive and thats the reason why wehr players have Tiger commanders in their load outs. And if wehr players really want to fight off efficiently against allied TDs they build the elephant.
So all in all i would like to see a clear role for the panther: Either it should be a pure TD or a good, highly mobile generalist - a better version of the comet.
No, the most problematic is cost/efficiency aspect. If it was cheaper and required lees tech, or if other tank destroyers were as expensive, then panther would make sense. Now it is overpriced. Its AI is also problematic as it works only very close range and then it could be satcheled etc. It's meant to be longer range unit.