vastly outdated and inferior to nearly all other tanks? not at all, it was better than the models it first encountered in africa (pz3, early pz4), and even later in the war it could hold its ground (and the later sherman models with a 76,2mm gun such as the easy eight were even better) against the 4s and stugs - of which the germans had the largest numbers, unlike the panther or tiger, both of which however were vastly superior to the sherman

compared to german tanks it was also much more reliable, easier to maintain and repair, and not a logistics nightmare (which the german heavy tanks were), it also had the advantage of having a stabilizer right from the start, something the german engineers took a longer time to implement and never so extensively

i think it is also important to note the early american tank engagement doctrine which called for tank destroyers to be the primary means of engaging enemy armor... with this, the fact that the shermans fared very well in their first fights, mostly adequately later and only were truly outmatched by the german heavy armor, and the logistics involved both on the ground in day to day battlefield conditions as well as overseas industry in mind, it is just nonsense to talk about the sherman being vastly inferior

There was some discussion fairly recently about the merits of the Sherman.

The Sherman was not, strictly speaking, "obsolete" at the outset of WWII. When the M4 Sherman arrived on the scene in 1942, it was more than capable in combat against the German PzIII and early PzIVs. However, continuing German tank design (influenced by the Eastern Front and the appearance of the T-34) outpaced America's significantly, as the US produced the Sherman en masse, rather than creating new designs.

As a result, when Panthers and Tigers appeared, the Sherman was simply outperformed. The terrain around both major American landings in Europe (the Italian campaign and D-Day) was favorable to the German defenders, and well-suited to the ambush-style tactics favored by many German tank aces.

Hard facts stood against the Sherman: the long-barrel 7.5cm of later PzIVs and Panthers and, of course, the German 8.8cm could easily penetrate the Sherman's frontal armor from over a kilometer, while its 75mm was wholly incapable of penetrating the frontal armor of most late-War German tanks.

The Sherman's inferiority can be forgiven against the Germans, simply because its virtue of quantity—which was an intentional combination of ease of manufacture, repair, and its mechanical robustness, all important for a long campaign—was more than enough to overwhelm the paltry manufacturing Germany was able to field in the West. However, the Sherman's inferiority is unforgivable in comparison with the T-34, which was produced in larger numbers and was superior in nearly every respect. One can only imagine how the Eastern Front would have looked with Shermans in place of the T-34. EDIT: Corrected according to ady's comments.