My wife has a 2009 Cayenne GTS a few months back. It was pretty loaded, 3 months old, and with less thank 3K miles on it. Sticker was 95K, I picked it up for 70K. So I can personally attest to options not meaning squat on resale. On the other hand almost everthing on the Porsche is an option - I'm surprised it comes with a steering wheel as standard
Having said that I do like some of the available options on the Cayenne such as the heated windshield. I loved that feature on the Range Rover as it made a huge difference with snow/ice buildup when driving up to the mountains. Wish it was available on the X5.
I do prefer the iDrive to the Porsche PCM touchscreen - maybe I'm just used to it. And the X5's heads up display is awesome. And nothing but nothing bets the BMW multi-contour seats
I do wish the X5M came with 19inch all seasons as options (the 2011 Cayenne comes with them standard). I know they are no substitute for true snow tires, but they have been just fine for me on my 07 4.8i through some pretty nasty snowstorms, and certainly better than the huge 20 inch summer tires on the X5 M.