My wife was looking at exactly this question. We drove the 14 GC diesel, the 10 touareg diesel, and the 2011 touareg diesel. We went with the 11 Touareg diesel used from a guy in Sacramento. It was in perfect shape and to be honest I think it is the best vehicle I have ever owned, and I have owned just about everything you could imagine. It has a range of OVER 700 miles and I swear if I had the patience to drive it 65 ish for the entire tank on a trip it would do over 800. The interior is amazing, it rides, drives, perfect and we have had no probs what so ever... That being said maintenance is expensive and it is surely not as capable as the 10 Touareg becuase it does not have the adjustable suspension, lockers, etc. However; we have never encountered a situation where the touareg did not handle what was thrown at it.
I have always been in love with the 10 and previous diesel touaregs but they are not as refined, but again the 11 is not as off road friendly. If you want a vehicle with incredible range, and plenty of creature comfort, with great reliability I would go with the 11 and newer... ALL that being said it is still not clear if or how much the diesel controversy will effect them.