http://www.tahoeyukonforum.com/threads/full-time-4wd-opinions.104267/
general motors makes a decent driveline. you just have to drain and refill both differentials and transfer case lube with quality product and then inspect it for leaks every few months. skim through the other posting that I linked for positive suggestions and feedback on the "awd vs. 4wd"
its all about preventative maintenance, really. you have these fools that think gear lube lasts forever and doesn't require servicing. when bearings get toasted or seals leak to the point of a low fill level, obviously you are going to have some sort of problem. there is no evidence that awd has more or less engineered or service issues than any other setup. just take care of your vehicle. crawling under there for a thorough inspection several times a year may be the difference maker as there is no warning chime for "low gear lube" or "transfer case leak"
I guarantee you, all of these folks bitching about failed diff and transfer case never once changed the oils, nor would they have replaced any parts if they even happened to look for leaks.
the nutbox who made the rant talking about "prefer real over fake" and manufacturer conspiracies regarding the awd platform was on narcotics. this thread prob should have been burned.