It's not unusual for these kinds of transmissions to do that. I know almost all of the Audi Tiptronic transmissions tend to have some hesitation or premature downshifting unless you put it in sport mode. The fix, atleast on those cars, was an ECU reflash. Hopefully someone will come out with a reflash for the Tribeca soon. It should make the shifts smoother and give you some extra ponies. Maybe Cobb is already working on an AccessPORT for it, who knows 
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