I have had two suburbans now. I normally drive fords but the suburban is just a better rig than the expedition and the excursions is just too damn big. Anyway, it is true that these vehicles have a few weak spots. I have done the intake gasket, the radiator, power steering pump but that is about it. Both my suburbans required the above repairs at the same mileage. They are very predictable and considering how heavy duty these rigs are, not too bad in terms of maintenance. There simply isn't anything out there that can touch the suburban for its combination of utility, comfort, towing capacity, and yes fuel economy. Pound for pound this thing is as efficient as a honda civic.
Power, room, towing capacity, turning radius (better than many cars)
The intake gasket problem on the GM as well as many others really needs to be addressed. I believe it is due to the use of plastic intakes. Go back to metal, it only saves a few pounds and the price is reliability/reputation...