Apples and Onions
You only can compare a long range Type IXD/2 with a fleet sub, mainly with a Balao (Both the german and american launched in 1943), because the Type VIIC was a much smaller, short range boat designed to operate in packs and closer to the home base. The US boats had to be bigger because they had to go farther -all away across the Pacific- and could not go back quickly to their home bases to refit. They carried therefore a larger load of torpedoes, much more diesel, storage for food and had better living conditions for their crews.
By comparing a Balao and a Type IX/D2, you can notice that:
Type IX/D2 has deeper crush depth
Type IX/D2 has slightly better crash dive times (Only 5 seconds or so)
Balao had higher surface & dived speed
Balao had longer range
Balao had larger torpedo load and bigger guns
Balao had way superior electronics (Radar)