With so few trucks ACTUALLY on the road, and being year #1 of production that's actually out there...
I'd say that almost everything you hear and/or read about rises to the level of rumor. It'll take a couple year's production to have enough on the road, and for the heavy users to show up any real, repeatable weaknesses.
Not that I would think there aren't any. There's a reason GM road-tests thier new designs with the customers buying the fuel (and license, and tires, and providing free "road time"), and no doubt we'll eventually find whatever weaknesses the package has, and they'll be obvious... Just like the 6. 5 turned out to be. In the meantime, I'd say that GM's probably in a near panic every time someone has a problem. This is one expensive and very much public experiment they are depending upon to regain market share...
So, your friend wants one, so long as he knows GM's history of doing R&D with the customer driving, then I guess all is well, and he should buy it if he really wants it.