There were some pretty amazing technologies on the allied side.
Im not WW2 expert, but there story of the Japenese sub I-52 always amazed me.
http://en.wikipedia.org/wiki/Japanese_submarine_I-52
They talk of the later war Allied ASW technology that is missing from all the WW2 subsims I've played. Todays sonar boeys, Ascoustic guided torpodos.
There is a recording of the sinking of the I-52 as recorded by the sonar bouys used to track the I52 floating around the internet somewhere. I listened to it a few years back, dunno..... it was really strange to listen to people... well... like that. The only recording I've heard like that,. I'll see if I can find the link.