In the end the main difference between German tanks and allied tanks was that allied built factories optimized to mass produce tanks, Detroit tank arsenal built more tanks than the whole german industry and still only produced like 25-33% of the total amount of tanks that USA built during the war.
To reach such massive numbers, the plant was built during the early 40s and have thousands of machines designed to automatize pretty much Everything in the production while the german tank production was using outdated manual work. A machine driven factory can produce much more at a higher quality than what humans can do.
If USA produced Panther tanks and Germany produced Shermans, the result would be the same and without all the problems germany had, the american Panthers would likely be of a significant higher quality.
Like warfare, production require massive amount of planing to be the most effective.
I wouldn't be that certain about the 2nd last bit.
You still needed the necessary rail infrastructure (e.g. rail carts with the necessary width) for transporting those vehicles to the coastal ports (either the Atlantic or Pacific) and have not only the ship capacity, but also the suitable type of cargo ship and/or amount of shipping capacity with which to transport those implements of war across the Atlantic and Pacific towards the front - along with their ammunition and spare parts - and in enough numbers to be tactically viable once they get there.
There is also the problem of providing ongoing maintenance support for those vehicles. The Germans and Soviets when dealing with heavily damaged yet salvageable tanks had the ability of simply towing those vehicles back onto train carts to be repaired back at the factory, or simply discarded and replaced with another tank as was frequently the case with the Soviets. With US tanks the idea of putting damaged tanks back onto ships and having them repaired back at the factory, all the way back in Detroit, was impractical to say the least.
That said, the Americans did finalize development and introduced their "equivalent" to the Panther (though to be fair it was much superior to it in almost every regard) by the end of the war on Europe. Yet even then, like the Sherman before it had to undergo a lengthy development cycle to ensure that it was not only tactically suitable, but operationally as well - being as reliable as the Sherman to reduce need for maintenance as well as being of the right size and tonnage to me transported by existing infrastructure (i.e. to fit on a rail car, light enough to be lifted onto ships by existing port cranes and so on so forth).
Overated and a failure.
It needed PZ IV escorts........
The only saving grace was its excellent gun.
You're right there.
I read that the gun, although great in an anti-tank role, was rather lacking in an infantry support role due the lack of filler they were able to put into the tank shells (a similar issue faced with ammunition used by Allied 76 mm and 17 pdr guns). Also something about friendly infantry being concussed by the muzzle blast whenever the thing fired off a round.
So basically it needed other tanks such as the Pzkpfw III (the TD variants primarily that is) & IV to act in a infantry support role whilst Panthers or Tigers acted in an anti-armor one for them. Somewhat similar to how American 76 mm and British 17 pdr armed tanks operated in a mobile anti-armor role, covering the more conventionally armed 75 mm armed tanks more suited for supporting those unfortunate footsloggers.
Even so, It was still a rather
fiiine looking hunk of steel ...( ͡° ͜ʖ ͡°)...
so my experience is soley based on using them in games ,especially in War Thunder 
