My parents gave me this car to my senior year of highschool with 245,000 miles on it. Currently it has 265,000 miles and is still going strong. We still haul a full trailer with it and it is working amazing. As the miles pack on some things have become a little faulty such as the AC only works sometimes but I can't really complain because the ride is amazing. I feel extremely safe in it (one time I hit a tree and it only left a little skid mark and dent on the bumper). The mpg is a little problem with prices sometimes but that's the price you pay for the giant engine. She doesn't seem to want to die anytime soon, the car is almost like a part of the family at this point.
Have had an 04, 09, and 2015 Yukon (my wife insists on buying these junkers). The 2015 is too new to tell the problems. The 04 and 09 both had oil pump die just past 110K miles, resulting in crushing of the cam shaft and requiring a rebuilt/new engine. Constantly having other problems with hoses, suspension, etc. All these generations of Yukons cost as much as a nice Mercedes, but is nothing more than a glorified S10 Pickup. I have had other GM vehicles from Cadi's to Chevy's. ALL have an expiration date before 150K miles.
It's hard to find this thing with any less than 100,000 Miles on it; however, even at this age and mileage it still rides like a your on a cloud. With the rear seat out and the mid seat down, you got 8' of cargo space. enough room to carry full sheets of plywood or sheet rock. The towing ability is wonderful; I can pull a 8x10 trailer filled with tools and supplies to a job with ease. Then with the seats up I can load the kid's string quartet with all there gear to the gig site in comfort. This comes at a price. On long trips, it's a nice car on the open highway with the family. While not too bad on gas if you take it easy, you're sure to see that gas gauge move if tow or hard accelerations.
Before i bought my Yukon, I rented them from Avis and Hertz. Loved driving them better than Caddy Devilles that I used to rent. Bought my 04 XL in fall of 04 and have never been sorry that I did. My first SUV..mid size SW before (Olds and Buicks) Drives like a car. My wife enjoys driving it. We have been on highway trips with 8 on board including all of the luggage. Amazingly the brake pads lasted for 80,000 miles before they needed to be replaced. Replaced them with original factory pads and they also lasted 80,000 miles. I like my 04 better than the newer 2007 to 2010 ones because of the folding armrests on the front bucket seats. The newer ones don't have them anymore.
Power and handling, for the size and weight, really impress me. 5.3 Liter has enough power for any loads. Visibility is very good. Even with 4WD It can go into any public multi-level parking garages. The Ford SUV has trouble doing this.
Only one improvement needed. A 3rd row seat that folds flat like the Ford Expedition. The GMC Yukon SLT XL beats all others except for the 3rd row seat folding /removal issue