oh man, if I would of had the AWD one I probably would of kept it. I do miss the TBSS for sure but a local guy wanted to trade straight up for an f350 power stroke so I went with that. I honestly debated a Q5 myself as a potential tow pig especially since I already have an R8, thought it would be cool to carry on with Audi.
I was really happy with the SS from a vehicle configuration standpoint. It worked really well when it worked. Mine had been stored in a garage for a decade in Winnipeg before I got it. So ALL of the rubber pieces were garbage. The guy who rebuilt the motor (at 10k miles) thought he was gods gift to mechanics, and he, well, wasn't. I was constantly chasing bugs and fixing issues, and all kinds of little things on it. In the 18mo I had it I put all new suspension (including airbags) on it. New tires. New alternator, battery, starter, and cables. New hoses, belts, water pump, and PS lines. Added a transmission cooler, added a larger radiator and electric fans. Fixed about 37 interior trim pieces, and little issues. Then I found a hurt head gasket about 3mo before the new baby was due to arrive and it just sucked the life out of that project. The Sierra had 36k mi on it, and warranty through 100k. Was expensive ($42k), but I drove it for 40-ish months and didn't do anything but change the oil.
I was really close to getting a Durango R/T when I traded for the Sierra. "Compared" the SS against a friends R/T a few times and would have him by a length at 35mph, then it was a dead heat to well into triple digit range. So, when the Sierra's time was up (for a myriad of reasons), I looked hard at an R/T again, but landed on the Q7 this time. We had an '06 A4 and it treated us really well. I wouldn't recommend an SS or really any German car to someone that can't turn their own wrenches. Shop rates are outrageous, and I can't imagine having to take something to the dealership every time I needed to address a small issue. We found that the A4 was about the same cost of ownership as our GM vehicles. Broke half as often, but cost twice as much. Really hoping the Q7 works similarly for us.
The Q7 is similarly fast compared to the SS and the R/T. It comes out of the hole a little soft, but the trans is programmed really well, and the boosted V6 has a nice tall and flat torque curve. The Q7 handles MILES ahead of the SS though. It really hides it's weight well, corners really flat, and those 6-piston calipers on 16in rotors make short work of stopping, despite the nearly 3 ton curb weight. Lots of "neat" features in the Q7, but the basics are still there in terms of driving dynamics and power to weight feel. The one thing the SS has done better than any other vehicle is the feeling of effortlessly accumulating speed. It just NEVER seemed to be struggling to accelerate. With a 4spd trans and deep 4.10 gears, there was no waiting around for the trans to shift and power to come on, it just effing went. Even in a 90-120 sprint, man, it just picked up and WENT. Only other thing I've driven with that kind of consistent pull was an old Grand National. Those things seemed like they NEVER ran out of steam!