Eclou, thank you for your summary (good initiative), please find my observations: (CCT08, log: ODO=2760km, 61hr, 45kph, 18.1 l/100km, 15.4mpg UK)
1) Indeed excellent touring car, effortless driving at low as well as high speeds, 1000km is nothing (Muscat to Dubai is a doddle). People in the back are very comfortable as well, especially with rear seat entertainment for the kids. I would recommend PDCC as this will keep her nice and level. Porsche's air suspension is spot on as the air suspension on my wifes Landcruiser is too soft and wobbles too much (overall 10 out of 10).
2) 4 zone air conditioning works well in 42C+/110F+ almost on a daily bases here. Get's cool air going quickly and cools down the compartment fast. However not as good as the Landcruiser's AC which would have turned me in the ice man if I had put it in low all the time. (7 out of 10)
3) Sound system good and easy to operate (Radio, CD etc), Satnav OK (haven't used it as yet, apart from the MAP), voice control fantastic, no AV input for IPOD. The rear view camera is a bit of a gimmick, nice to have but its use is questionable. Phone facilities are great and people come through nice and clear. I have though a problem with my dual sim (sim in car) as the sim card doesn't seem to disconnect leaving my gsm not picking up any voice calls (as soon as I use my gsm all is OK again) (8 out of 10)
4) I have noticed a slight judder as well (remember that you very quickly get used to the limo driving conditions hence every little judder, creek and noise is noticed --> only be the driver though) however I think the slight hesitation is because in non SPORT mode the car gears up (6th) quickly hence needs to gear down to accelerate. I normally don't go hard on the throttle hence it takes slightly longer to gear back. Talking about noises  'creeks', when the car is hot I have a creek coming from the dashboard on the passenger side, I haven't managed to locate it, it's annoying though (9 out of 10)
5) Comparing the break dust with my BMW X5 (4.8is), I think the Cayenne has far more break dust making the alloys dirty very quickly. I like my car spotless and the alloys take most of my time to clean (try to wash your car in 44C
) (7 out of 10)
6) Average consumption significant and I do approx 410km per tank(+/-88ltr, 12ltr reserve). (7 out of 10)
7) Twin turbo Engine, one word fantastic however I have a slight 'whine' at 1500rpm (can be heard stationary while pushing the throttle) Again I am probably far to sensitive but I have mentioned it to my dealer and they are going to look at it at the first service (3000km) (9 out of 10)
8) Tiptronic gearbox is very smooth, you hardly notice changing gear (Smoother than my X5 and Landcruiser). I sometimes think she is gearing up to quickly. Definitely no 'neck' breaking as I have seen threads of. However she gets far more sensitive to the throttle when in SPORT mode, what could do some damage if you floor it. (9 out of 10)
9) The active cornering lights is a fantastic feature and very handy. The headlights should be turning while cornering as well (slightly) however I haven't noticed this as yet (9 out of 10)
10) She has good luggage space and the auto gate in my opinion is a must. I have the full height plastic liner in the back what keeps the compartment spotless
11) Overall, definitely the best car I have owned so far, even wifie likes it. (9 out of 10)