All in all the Sherman BETTER be better. It is an about 5 years newer design. Not just that, the Panzer 4 design was done at a time there was no real “yardstick” for a modern tank (WW2 era) design. The US designers also had a look at P 3 and 4 characteristics when designing the Sherman, so I heard.
I don´t accept the “ease of production” song and dance either without someone doing a whole lot of research, methodical counting of welds and components. Without a book or thesis by some student of mechanical engineering, count me sceptical.
Same goes for the reliability thing. I doubt there is a large difference. It seems one would want the Tiger and Panther reliability standard to apply to the smaller P´s too.
(Some account has to be made to the differing capabilities of the maintanence and spare parts availability of German and US repair units. Concerning engines, somewhere along the TN history mention was made of miserable German motor oil quality. For that they held up pretty good.)
The P 4 is good tank and compares well to Sherman, is NOT outclassed by the Sherman and was able to do it´s tasks as well as the Sherman.
Try and compare what P 4 were up against and their value and same for Shermans.
Oh yes, something the youngins of today can relate to : the Panzer IV has BETTER gas mileage !
Sherman : 340 liters per 100 km .
Panzer IV : 225 liters per 100 km !
I don't have it with me, but IIRC Zaloga's "Armored Thunderbolt" book covers this fairly well with researched numbers>