I have just driven one too, my S8 D2. I bought the first one I saw so didnt test drive any others.
Only other Audi I drove was a rented A4 1.8t auto in Switzerland, that was quite good too.

Sadly a big fat "0" just joined up to do some research on them always wanted one since watching the transporter but never had the money to buy one, and I've only just turned 25 to insured on one. :) but there's never any harm in window shopping lol

Just to update this, add my current D2 2003 S8, so that's 3 I've driven a fair bit.
And thinking about it I've probably driven 3 or 4 others (all S8's) when looking to buy.
The 1998 S8 which I had for nearly 11 years was, I discovered recently, an ex Audi marketing car used at the Motor Show in 1998, it is now owned by IT.