I bought it new and during three years I've had only one major repair out of warranty (power steering box). After 65,000 miles it still rides great and is in excellent shape inside and out (other than normal minor paint scratches and dings). The build quality is excellent and the car is holding up very well. I have previously traded my car every three years when I get tired of them, but I want to keep my Yukon XL until the wheels fall off.
The big comfortable soft leather high back bucket seats are great and very comfortable. I test drove lots of SUVs and these seats were the greatest and were a major factor in my decision to buy the Yukon XL. The sound system is excellent too.
If they could improve the gas mileage without killing the performance it would be great.