Hi Paul,
I test drove both and got the Touareg 2.5TDI Auto. The build quality is much better and feels like it is made from granite.
It tows really well and returns about 25mpg while towing, about 30mpg without. There are lots of bells and whistles in the VW and the sat nav is a dream.
You also get a day out on VW to been shown what the car can do, a half day on the track and a half day up to the axles in mud. I went to an estate in Gloustershire. Fantastic day out and all in VW's own cars!
The other advantage with the VW is that it is not as high as a lot of 4x4's and you can get into multi story car parks etc.
Kerbweight is 2500kg so it will tow anything on the market.
Great car! Try it.
Hope this helps
Mark