The Cadillac had a lot more carrying room if you folded the third seat into the floor. It has an electric motor that helps with this task. Headroom is nearly the same front and rear of these two, but the Cadillac has more rear legroom. The Porsche has the far better rear seating position.
In terms of safety, the Cayenne's crash test findings have not been completed while the Cadillac does well in all areas. It is not as top heavy as its sister ship, the Escalade, and is much nicer handling. The Porsche has front, side and side curtain airbags, four-wheel antilock disc brakes, electronic stability control, and the outboard positions have belt pre-tensioners. Cadillac matches those attributes.
Of the two, I liked the Cadillac very much despite an interior that was very plain, difficult to read gauges, and seats that never proved to give me comfort. It was not as eager to please you while driving as the Porsche with it quick reflexes and eager transmission kick-downs, but the SRX was friendlier. The touch screen monitor was easy to master, except for the GPS, and the OnStar always makes me feel more secure. Although I quite preferred the sound the Porsche made when urged to merge to the guttural bellow of the Northstar.
In addition, I appreciated the rear cargo area and the optional entertainment DVD package the SRX provides. I also felt it was easier to get in and out of and looked sharper. As for the Porsche, it had much better seats, handled better, and tied with the Cadillac for having the most easy to dent side panels in the grocery store parking lot. If you have a fussy husband it is going to be difficult to hide any dings from the large, flat sides these two-ton vehicles flaunt.
Dad's view: Except for the electrical door problems with the Porsche and the gas mileage, the Cayenne was a joy to drive. I liked the shift paddles on the steering wheel, the way the engine effortlessly allowed you to take command of any situation, and the brakes. The Cadillac was too cushy for me.
The Internet is filled with negative comments about the Porsche's fuel economy and difficulties with the remote locking key. There were also concerns expressed about excessive tire wear, lack of a good air-conditioning flow to those in back, complaints about the Volkswagen Touareg offering nearly the same package for less money, and the lack of storage space. We agree with all of these insights, but we also agreed on the many positives that emerged during our evaluation and that included the handy adjustable ride height, smooth suspension, granite like build, and energetic engine.
A while back Porsche was supposed to be considering building a four-door sedan, but the idea was shouted down. When the SUV emerged from Porsche's factory there seemed to be less resistance to the idea of a non-sports car from this legendary builder. If the sedan Porsche was thinking about had anything like the handling and power of the Cayenne it would have been a great car. As it is, the Cayenne is certainly one of the best performing SUVs available and with a new, much less expensive, six-cylinder version available, it should have a long life.