Took a tour recently at the Museum of Science and Industry in Chicago. The U-boat had 2 Enigma machines and a codebook, but to my knowledge, Enigma had already been cracked by the time of the U-boat's capture. My tour guide indicated that the capture helped "end the war a few months early", but was light on details as to how or why. If that claim is true, what are the "how and why" of how the capture aided war efforts?
I've done a little bit of reading on this since reading your question and I would put forward the theory of "tour guide exaggeration" that would explain it.
It seems that while the capture of the Uboat provided intelligence that could be exploited in the form of the machine and the codebooks, the fact that Enigma had already been broken meant that the capture, in fact, was a bit of a hindrance in some ways.
I say this because it turns out they had to keep the crew segregated from other POWs and they had to keep the entire capture secret so that the Germans didn't even begin to suspect that the codebooks and machine could have been captured.
The intelligence from the codebooks and associated documents did help in one way- while the Enigma codes could be worked out when the key changed it took some time and those documents provided that key for the next few months after the current one had expired. Whether or not it shortened the war effort is hard to tell but personally I would doubt it.