I drove the 6.7 a few days ago, and I have to say that it ROCKS! I have no other diesel experience than that, so I cant make a comparison :/. If you want more info, I have found quite a bit on Ford's web site, and there are a few articles about it on different truck web sites, I would say google it
here is a link i found that seems to be pretty accurate.
All-new Ford designed and built 6.7L diesel for the 2011 SuperDuty - CleanMPG Forums
good luck finding more
