First, the useful: About 14 inches of it goes to wheelbase, and most of that goes toward making the third row both a little bigger and easier to get to; access is easier, too, thanks to a wider door opening.
The issue that some might find is that at more than 220 inches long the XL is just too long either for garage spaces. And being at the helm of one of the longest vehicles available might complicate things when it comes time to park—or to maneuver through the tightest city streets.
There's one other key difference for the Yukon XL: On some of its variations, you can opt up to a 352-horsepower, 6.2-liter V-8 that's an even better choice if you happen to tow a trailer very regularly. Otherwise the base 320-hp, 5.3-liter V-8 is a better pick as it's very smooth and strong, and much more fuel-efficient.
Otherwise, it's much the same inside as with the standard versions of the Yukon. The one significant packaging flaw is that the third row isn't roomy enough to be practical, yet to get it completely out of the way for cargo you need to remove it from the vehicle—a physically demanding task.
Just as with the standard Yukon models, the Yukon XL is offered in SLE, SLT, and top-lux Denali models, with the latter offering essentially the same level of luxury (and the same 403-hp V-8) as a Cadillac Escalade.
For more information on the GMC Yukon XL, see our full review of the 2011 GMC Yukon.