Porsche Cayenne seems to be the best in the biz in terms of the 5 door Crossover built for driving, you are paying MSRP (or close to MSRP) for the best auto engineering can deliver. That said, the Cayenne doesn't contend with Audi, VW, BMW, MB, or any other luxury crossover; its in a class of its own. Yes Maybe the X5M, ML63, and Audi Q7 V12 TDI seem like alternatives, but really cant offer what Porsche offers; pure driving bliss from a huge automotive racing database and components that are really tried and tested from being fitted to their other product lines.
In my opinion this is how i see it
BMW X5 (current generation isn't really a contender with the new Cayenne, the F15s will be on equal playing fields, but still carry the motto that the E70 has)= Built for driving your young to middle aged family around town, but with added satisfaction of knowing that when the road gets curvy, the car will be able to cope with it well.
Cayenne= Car that was designed for high speed and high cornering abilities. In terms of family friendliness, who cares, as long as the driver has a huge grin from cheek to cheek.
Thus, the idea that the Cayenne is in a class of its own, comes into the picture.
BMW and Mercedes Build Beta Products!
Lexus build Release Candidate Products!
Why does this matter?
CAUSE EVERY TIME someone says Lexus has better build quality, one should consider what Toyota their Lexus Engine and chassis platform comes out of and how long that part has been tested in the real world!