I can't comment much on what to look for etc as mine was nearly new when i got it from Audi so I didn't do much research. However, day to day running so far is great. The commute is an absolute pleasure due to the combination of creature comforts, seat comfort and DSG box. I just cruise into work and don't feel the need to cane it in order to enjoy the experience (unlike in the exige). Everything's very relaxed. It's pretty good fun when you do cane it though as the engine sounds fantastic and the quattro does a decent enough job. I guess it's not what you'd call a sports car by any stretch, more of a grand tourer in my mind.
I really love mine, and am really glad I went for 3.2 rather than S3 (no offence S3 owners - it's just what I preferred)