Well considering the T-34 is an 1940 vehicle... it's fairly good.
Pz4 is a 1936 vechicle...
Nobody says T-34 was terrible (or even bad), but it`s reputation and it`s actual performance in 1941-1942 are quite different. It was a good tank, that scored amaising luck in that Paton, soviet engineer, created a way to weld it`s armor with minimal usage of human welders(in 1942), which didn`t work for thicker armor plates for some time, that made T-34 production amaisingly efficent with Soviet workforce. Also was the reason T-34 was not replaced nor up-armored during war.
In fact, T-34s manufacturing optimisations could be a subject of a book itself. But, that happened later, by which time T-34s advantage in armor and gun faded, and it was just a good, cheap, reliable vehicle.
You points about the panther are fairly moot. The suspensions is so over complicated that virtually every modern MBT uses the same torsion bar suspension system (and has the same issues) and they manage fairly well.
None that I know uses similar weels arrangement, it is inefficent and mainenance intensive. Also, you might notice a problem with your argument,
modern MBTs are
not tanks from 40s, not is there currently a race to produce thousands of MBTs every month.
The gun was also equally as effective against infantry as the long 75mm guns on the Panzer IV and the crews never felt that it's anti-infantry capabilities were lacklustre.
Not sure, seen quite different oppinions on Panther`s HE shell.
The main issue is the gearbox due to weight. *However* by the time the Panther overtook the Panzer IV's in number on the field they had virtually identical reliability rates. While it's hardly a miracle weapon it's issues are largely over exaggerated just in the same manner the shermans are.
Which, I would assume has to do with degradation of Pz4 manufacturing due to strategic bombings and cost cutting, frankly.
Panther was too heavy. An earlier version of vechicle or other prototype could be lighter, which would solve the problem.