I can give you a very honest and accurate opinion. My partner and I decided to buy new work vehicles the middle of 2004. He showed up one afternoon with a Silver on Silver Cayenne S with 22" 3 piece wheels. I do not like Cayennes but I must say his is very nice looking. Me. I wanted to order a 4.8is as an owner of a 4.4i sport, I was eager to get my hands on this toy. I drove his many many times and compared it to my 4.4i Sport and still preferred the 4.4. It felt quicker and more responsive. Not to mention the fit and feel. Close the door on an X5 then close the door on a Cayenne. Huge diffrence. I thought the Cayenne was smoother on the Hwy but for around town and all around opinion I still preferred the 4.4i Sport. Obviously he preferred the Cayenne. Then my Imola Red Beast finally arrived after waiting for it to be built. There is absolutely no comparision between the 2. Now my partner is no sloutch behind the wheel of a car. He has raced professionally in Europe and South America in LM and Prototype. As a measure of his talent we have a Racing Kart track in our area and alot of Professional racers keep in shape there. One night he was matching lap for lap with Roberto Moreno. Needless to say he is pretty quick. He got behind the wheel of the 4.8 and immediately feel in love. Instantly wanted to get rid of his beloved Cayenne. But he did not want to buy a 4.8 as I already owned one so he went and traded his S in for a Cayenne Turbo. Now after he and I driving both in length we have came up with this conclusion. the Turbo is only slightly quicker. But quicker. 4.8 handles better, rides better, and all in all alot more fun to drive unless you want to Stop Light Drag Race. No question even if they were the same price we would both choose the 4.8. I have my resonator removed and the sound is soooooooo sweet. I must say I have about as much fun messing around with my 4.8 as I do with my Yellow Bull. No joke. I have never had so much fun in a vehicle(aside from the Lambo) as I have with this 4.8. Ive had alot of fun cars including: Ferrari 355, Ferrari 348 Speciale, Ferrari 360 Modena, Acura NSX, Lotus Esprit S4S, Lotus Esprit V8, Modified Supra Twin Turbo, etc. Never have I had so many people come up and gawk and ask questions and get the very common "thumbs Up" from other drivers. It may be in part from the sound of this beast but I love it. So in short.......4.8is is an easy decision over an S and in our opinion(1 owns a Cayenne Turbo) we both prefer my 4.8 over the Turbo as well. We will be putting both Vehicles on Moroso Race Track in the near future and will let you know what the results are.