APT wrote:
Half ton should be good for you then. If you can afford a 2007+ GMC Yukon Denali or 2009+ regular, you'll be a lot happier with towing performance with more power and far better gearing.
Getting a newer 6-speed is definitely worthwhile.
We've done some side-by-side comparisons of the 4-speed and 6-speed both towing and not towing, and the 6-speed makes a significant difference in both cases.
The 2015.5 Yukon XL Denali introduces the new 8-speed to the Suburban family of trucks, and I'm looking forward to see how that affects MPG and towing. As far as I know, the Denali is getting the 8-speed first, then the Cadillac Escalade, and then later the Suburban.