The QX-56 is the best SUV secret out there. Stunning fit and finish inside, and excellent engine -- torque and power (mileage is poor though). We get 13 mpg in city driving and 16 mpg highway. If you drive 55, you'd be able to coax 17.5 or 18 mpg highway. Beautiful leather and wood accents. Electronics are abundant and XM Radio is terrific. Not a "beautiful" car on the outside, but still the best I've owned.
Engine torque, tight turning radius, wonderful suspension, roominess, electronics, leather & wood, fit and finish, flexibility/features. Infiniti dealer service.
Trite but true -- mileage. Not sure how one would squeeze better mileage out of this car -- perhaps a turbo-diesel or something of sort.