My wife and I love everything about this vehicle (except my wife complains that she never gets to drive it). The interior improvements over the previous model are incredible. I knew GM could design an interior this well if they put their minds to it. Exterior styling is good, could use a little more uniqueness. However, I still think it's look uplevel (my nephew thinks it's the new Denali). Now have just over 8k miles on the Yukon and gas mileage is OK -- 11-15 city / 15-21 hwy. I switch a lot from E85 to reg unleaded. However, in the last 1k miles, the mileage has greatly improved (coming out of winter doesn't hurt either). A definite good buy.
Bose stereo, AFM, great steering (tight), excellent road manners, very quiet.
No improvements to mention to date. Everything I expected of this vehicle and more.