That's one reason that the failures are overlooked. In other words, because eventually things worked out, we don't judge the entire effort as poorly as it should be.
As for the platform itself, the only comparable vessels built in numbers were the Japanese fleet subs and the German IX class. I'm not sure how directly comparable the three nationalities are with each other; all suffered from the large size making them slow to submerge and not as maneuverable underwater as the non-fleet subs (German type VII, US S-class). The German boats were able to reach far greater depths than the US boats, and that and speed of submerging are two of the important defenses of the boats. A direct comparison would be interesting, especially on time to submerge, turning radius submerged, deapth changes submerged, battery endurance, range.
I suspect that the German boats were superior in most underwater agility categories. But it's like comparing the Sherman, T34, and Panther. Each had something the others didn't.