Panther or Comet - which would you prefer?
In vacuum or in the context of the faction they are in?
Against what kind of target?
What situation?
The choice isn't obvious here, even for me, but I'd personally go for panther for the possibility of panzer tactician, MGs being decent vs inf while stationary, greater survivability in general and better vet(vet2 to be specific).
Comet will end up with greater firepower at vet, but it'll be just as squishy as vet0 one and I prefer to outlast then to outgun.