The ad says it (S8) shifts smoothly with no issues. Here's the link to it: http://seattle.craigslist.org/see/cto/4123121777.html
Now there's another pick just down the street from me, a 2004 A8. I think I would prefer the sportier S8, but having never driven an Audi before, I don't know how much better the S8 would be vs S6 with V10, and now the A8. The ad above for the S8 sounds good with clean title and all, and when I contacted him regarding proof for all work completed, he says he has the receipts and did the work himself. This is fine with me as I do all work myself too and a skipped tooth on the timing belt shouldn't sound or perform well.
My wife is now leaning towards the A8 down the street, from a stealership that wants 14900, with 105k miles. I still have to call them to find out about the status of the title and if the timing belt was done. Assuming the latter was done based on miles, but you never know. Thanks for the quick reply.
So in summary the current choices are:
1. 2001 S8 with 110k miles and recent timing belt and water pump
2. 2006 S6 with 42k miles and V10 engine
3. 2004 A8 with 105k and unknown title and timing belt status for now.