I bought a 2006 XT. I love it. It is fast, comfortable and cruses on the highway with ease. The agility is unbelievable and when you drive it, it feels like a bigger car. The automatic transmission downshifts quickly and smoothly. I have one problem; my wife drove it and now I have two XT's.
Engine response, steering response, radio, seats, "the feel of the road", the room, and the appearance.
Not much to improve. The gas mileage could be a little better. But I wouldn't want the improved gas mileage to take away from the performance. So I think that the gas mileage is just fine.