Feel free to differ. The T-34 was fast only because it had no armor. The gun was the only thing good/dependable about it. The Christy suspension was fine but had nothing to do with how well the thing operated except for being so light it could fly across a field. German gunners routinely hit the things due to their superior turrets and optics. The turret was ridiculously small and difficult for the gunner to traverse and could hardly see out of to target, so they maneuvered close to get a shot, which caused the death of many Soviet tank crews.
I will differ, thank you. War is all about investment. You have to choose the best tactical and strategic paths and develop technologies to support those paths in parallel. We chose the M4 and even though it was easy to produce and reliable it was also a death trap for hundreds of good allied crews. It was too tall, so it was visible at great distances, the 75mm and the later 76mm guns were far less deadly than the German counterparts. We built hundreds and lost hundreds. Like our miserable torpedoes, we had the wrong people deciding our technological paths for our tanks, particularly since we had a wealth of experience by 1942 available for our use.
The Germans had an undeservedly vaunted reputation for their stuff too. They made stupid design decisions throughout the war. Both the Panther and the Tiger were maintenance nightmares and couldn’t go significant distances without replacing tracks, transmissions, or engines and sometimes all three. They did have fine optics, guns, and ammunition and good frontal armor but they were slow and few in number compared to us and the Soviets. They also had really funny excursions in wasting effort, like their monster siege guns and Porsche’s useless Elefant and Maus.
The T-34 on the other hand, was fast, had good cross-country mobility, reasonably well armored, had excellent guns, and was useful at all temperatures, unlike the Panther whose interleaved road wheels froze together on cold winter mornings.
Remember that the Germans lost, big time, at Kursk and every battle after thanks in part to the T-34 and the dang T-34 was still a problem for us at the Pusan perimeter in Korea, five years later.
You judge a technology on how well it performed its mission. In this case, it was an excellent design and an excellent balance of characteristics. And the silly Nazis lost..