Get the Tahoe. Its nicer looking, better built, and gets better mileage. The GMT 900 platform considered to be at the top of the full size SUV choices.
The QX56 and its twin the Nissan Armada was the least reliable vehicle sold in the US for awhile. It was 300% less reliable than average. Even if its improved its still the same SUV since they havent come out with a new model yet.
