This thread has been dormant for a while, but it I think it is also worth noting that the NNBS (Suburban or Yukon XL) 2500 models have 39 gallon fuel tanks. This does make a difference when towing long distances. I also have to say that pulling my 23' Toy Hauler loaded to the max (~8000lbs) with the 3/4 ton I do not feel the trailer is overpowering the vehicle. With my 2005 Ford Expedition it always felt like the trailer was controlling the truck and I was always paranoid when in wind or next to semis. The Expedition also sagged big time and I had to crank the tortion bars. With the 2500 the truck sits level without even putting the tortions on the weigh distribution hitch. I can actually set it to one link less on the weight distribution and don't have to put so much tension on the trailer hitch. With the 2500 I feel like I am in complete control and the integrated brake controller works flawlessly. Towing mode is also very cool with the downshifts to help slow down, higher RPM shifts, and downhill speed compensation. There are also the little added perks like the auto-blinker timing is longer when towing than when not towing and with towing mirrors you have awesome visibility. If you can put up with the rougher ride I definitely recommend getting the 2500.