I had a 2011 GMC Denali XL with the 6.2/6 speed.
I have a 2014 Jeep Grand Cherokee with the 3.0 EcoDiesel.
The GMC was used as a secondary tow vehicle for my 7000 pound boat. I've used the Jeep a couple of times to tow the same boat.
I love my Grand Cherokee. Might be my favorite vehicle I have ever owned. The 3.0 with the 8 speed just drives great. While I haven't pulled my boat through the Rockies, I was never left wanting for power driving I76 (relatively flat). I know it wouldn't pull up the hills as fast as the Yukon, but I think it would do fine. The GM 3.0/10 speed should be a better combo than what I have.
If GM would have offered the 3.0 diesel in a Yukon/Burb when I was buying at the end of last summer, I may very well have ended up in another GM SUV vs the Expedition that I bought.
2012 RAM 3500 Laramie Longhorn DRW CC 4x4 Max Tow, Cummins HO, 60 gallon RDS aux fuel tank, Reese 18k Elite hitch
2003 Dodge Ram 3500 QC SB 4x4 Cummins HO NV5600 with Smarty JR, Jacobs EB (sold)
2002 Gulf Stream Sea Hawk 29FRB with Honda EV6010