Great idea! I currently have a truck camper on a big-block 4x4 3/4 ton Ford - it is such a pain to get ready, drinks so much gas (<7 mpg I kid you not), and handles so poorly that we never use it - it just decorates the local RV storage yard. We are thinking about a compact little Westfalia too.
How do people like the pop-up roof and the upper bunk? Since we have little kids, that's a feature that catches my eye.
I found this inspirational site about living in a Wesfalia:
http://www.cs.rochester.edu/u/jag/vw/
Edit: corrected the URL.