We have owned 4 GC's altho none of them were diesel because the Ecodiesel wasn't available when we owned ours. We never had a problem with any of our Jeeps.
We bought a Touareg TDI Lux new in 2011. I cannot say enough about the quality and the ride in this SUV. We have towed our Golf on a dolly behind the Treg w/o issue.
We have only had one issue in all the years we have owned the Treg and it wasn't mechanical. It was a hard drive failure that was taken care of under warranty. The mpg's we have gotten with this car far exceeds the ratings, in some cases in the mid to high 30's.
We have looked at the new GC, particularly the interior. The Treg, while understated inside, in our opinion is of higher quality than the Jeep.