Sorry for overlooking this topic, but I may be able to add a little real life input.
Our 2013 Touareg TDI has towed approx 4500 miles in its short working life, the latest a trip halfway across the country for a total of almost 4000 miles pulling the Burro
I will try to give you a comparison with the '99 Honda Odyssey we used to do this for about 12 years. It was a 210 HP with a 4-speed transmission, two extra transmission coolers, a transmission oil temp gauge, and helper airbags in the rear.
It was all but mandatory to tow in 3rd gear, resulting in about 3000 RPM, because anything except a slight downgrade, preferably with the wind following, resulted in frequent downshifts. The Honda, pulling about 3300 lbs was near its rated limit, and the constant slowing down for the slightest hill kept average speed fairly low. We averaged 15.6 mpg, which I think is pretty good. The engine noise from the elevated RPMs were a bit of a pain, always reminding me that I was torturing the thing. Reliability was excellent, probably because I lucked out in getting a tranny that was OK.
We decided to confer the Honda on my son while it was still OK, then looked for a tow vehicle with a much wider margin for error. Having had some experience driving a diesel in Europe we looked at the Audi Q7, Touareg TDI, BMW, Porsche Cayenne, and the Mercedes (not seriously). The prices were horrifying, and it took a long time to come to terms with it.
As has been hinted at, the social stigma of owning a Merc, Audi, or BMW was real for us, so the Touareg became the frontrunner, with the bonus of a lower price. An aside: the marketing strategy for VW seems to be to offer about half a dozen levels of trim, with no real options available. With minor gripes that was fine for us, since by the time the others added the necessary options the prices had gone through the roof. Styling also played a small part: I prefer the smooth muscular look as opposed to the "bad origami" look of two of the others.
The diesel was the only choice for us, so we got what we expected. I find the low end (1750 to about 2300 RPM) torque peak just right, especially when the 8-speed tranny is able to keep it there when needed. 406 pound-feet of torque is quite a lot, and the pulling power is strong, quiet, and uneventful.
The 280 pounds of tongue weight
turned out to be negligible for this setup, and stability has been flawless. VW does not endorse weight-distributing hitches. Connecting up the trailer activates some changes in the transmission shift points, cooling system, etc. and activates the car alarm if someone tries to unhitch. I use a Prodigy RF brake controller, and there is what for me is a perfect place to put it, no connections to the tow vehicle needed. All in all a fairly uncomplicated hook up process.
On the road the performance and behavior is of the "now I can exhale" type: quiet, smooth, and with gobs of reserve. On the interstates I set the cruise control to 65 to 67 and let it go. It takes extreme conditions to force it to slow down, otherwise no drama. It seems happier at 65 than at 63, because the transmission is more ready to shift down on some hills just to keep the engine in the "lots of reserve" band and free from lugging RPMs. A pull up the notorious hill on 95 north of Lewiston, Idaho was an eye-popping experience.
A rear-view camera that had been previously attached to the back of the trailer was hooked up to a screen which fit nicely in the pop-up compartment on top of the dash.
There is no provision for engine block heating, and when cold one just flicks the switch and wait for about one second and the engine starts.
With the quiet performance comes the extra awareness of tow bar sloppiness, which I cured with the "Quiet-Ride" device. Works nicely.
Overall I got what I bargained for, at about $48,000 and the contrast with the Honda, good as it was, is huge. Unfortunately I haven't calculated the actual fuel mileage for our trip yet, but earlier figures had it at between 18 and 22. At a distinctly higher average speed. Without the trailer I get between 32 and 33 mpg on the highway. Our trip revealed some pricing quirks for diesel, but it was generally right in the mix, so the expected diesel premium did not materialize this time. On an earlier trip I encountered a "boonies" gas station also offering diesel but the nozzle did not fit. The much extended mileage range on a tank helped, but I have since seen a portable nozzle adapter for sale
which would make it possible to fill up from such pumps.
If needed, please PM me for additional information. We're happy.