the Panzer is a death trap. PT boats have a better survival rate against aircraft.
Seeing that the others have addressed most of the other points, I would add the popping a PT boat is far easier than popping a Panzer.
Last night, in a La-7, I had to make multiple low speed passes on a panzer to get the kill, while I can kill a PT in one pass with a small amount of ammo.
I would have to say that disabling a panzer with a plane is way too easy, but it will definately survive longer than a PT boat. Once the turret is disabled, you might as well have been killed.