Each to their own, but the X6 is no beauty either. And, money no issue, would anyone seriously chose a BMW over a Porsche? Sorry, but the BMW badge just doesn't have that sort of reach.
I've had my 2009 Cayenne GTS since new, after a couple of BMW M3s (both E46s) and I'm delighted with it. Wins hands down on build, handling and enjoyment, as well as the noise the thing makes. Its as quick as you could ever want to go and is also much more exclusive than any X5/6. Again, each to their own, but I think it looks great. Cayennes have been let down before by Porsche fitting tiny wheels to such a big car, but I ordered mine with 21" body-colour-matched wheels and it works well.
Do agree with others on the look of the new one - its odd....but then, people where saying that about the new 5-series when it appeared, but we all love it now. We get used to it. The M5 is one of the best cars I've driven.
On MPG, I get around 19/20 from mine around town and 25 on motorways. Again, far less economical than other cars, but its powered by a 4.8l V8, so be realistic.
GTS is also a considerable step up from the S, in terms of performance & quality, whereas the Turbo is plainly mad. Try one, you may be converted, you may not.