Tourist, thanks for responding. Your reply made it in while I was typing mine. So you have used M770 hubs and haven't had any problems? Great!

Yeah, I can google "XT M770 failure" and get a few hits. Do me a favor and google "Rohloff failure" and see what comes up - lots more hits. And yet the Rohloff is the reliability darling of the touring set. Hmmm...

You selected M756 hubs for your touring bike because you "took it as an endorsement" that because Surly equipped the BD with these hubs, and the BD is a cargo bike, that they must be stronger, right? Perhaps you should have considered that Surly used M756 hubs on the BD because the BD is equipped with Avid BB7 disc brakes with 6 bolt rotors and the M756 was the last XT hub to come with 6 bolt I.S. mountings (newer XT are Centerlock). Again, correlation does not imply causation.

If we took what Surly equips its bikes with as a quality "endorsement" then LHT owners should be tossing the front and rear derailleurs because the 2012 LHT comes with a Sora FD and an LX RD (instead of the Tiagra and XT of previous years). Personally, I think that Surly is just trying to save a few bucks.