I wouldn't consider a high mileage auto. i've rarely heard of manual gearbox problems on VAG forums, but that isn't the case with autos. Multitronic seems particularily prone to issues & very expensive to repair. IMO you'd be crazy to take any chances.
I think you're right, the Audi multi if made of butter, and the tiptronic is only available on the 2.5tdi engine and that also seems to be made of butter too.
As much as I fancied another Audi I think I am going to go back to a BMW or Merc, just think as an older car they have LESS issues, they are far from issue free, Mercs have rust issues, and BMWs tend to like eating swirl flaps, but they are things that you can see or sort for peanuts.
The 2.5tdi I looked at had its belts down 5 years and 72k miles ago, so it would have needed that doinng, so another £600 at least, just starts getting too expensive.
As much as I would like a manual 1.9tdi I know that after a few weeks I would regret it.
Thanks for the info guys, a few things I had forgotten about Audi ownership.