As long as you're not penalizing adults with a ride in the third-row seat, the GMC Yukon does just about everything you can rightfully ask from a large sport-utility vehicle.
In either of the two body styles (standard and stretched XL), the Yukon has massive space in its front two rows of seats. The seats are fairly wide and flat, and taller drivers will find the windshield header sits fairly low--while the seats don't power down to a driving position that's low enough to see stoplights easily. It's not unique to the Yukon, but it's striking in such a tall vehicle. Getting into the seats is more of a clamber than in, say, an Acadia crossover, too. Second-row seats in the standard Yukon have good leg room, but the stretched Yukon XL improves even on that space.
That Yukon XL adds about 20 inches of overall length to the stock truck, with 14 inches devoted to the wheelbase. The stretch makes the third-row seat more accessible, and adds more cargo space in back, but the space in back is still only suitable for kids. The combination of a high step-up and a narrow opening to clamber through are amplified by a low seat cushion and a high load floor, which doesn't leave enough head room for adults.
In the standard-length version, there's very little space behind the last row; it has 108.9 cubic feet with the second and third rows down, but just 16.9 cubic feet with the third-row seat raised. With the third row removed and the second row folded, the Yukon XL has a huge 137.2 cubic feet of cargo space, and there's still respectable room for cargo with people in all three rows. In either version, the third-row seat doesn't actually fold into the floor when not in use; it needs to be lifted out of the vehicle, which is really a job for two people.Fit and finish inside is generally top-notch, the interior is pleasantly free of wind and road noise.