I hope replying to myself isn't a sign of impending mental illness.

Anyway, thanks for the responses to my question. I wasn't satisfied with the audio clips available on the internet so I asked my tuner if he would call me when he had other turbos in the shop with different exhausts so I could listen to them. He obliged, and I was planning on having him order and install my exhaust anyway, so it turned out great. I listed to sport, stock, Milltek, and AWE. As soon as I heard the AWE I decided I didn't need to listen to anymore and ordered one for install when my TT arrives in the next week or two. He said none of his customers with new exhausts had any warranty issues with the Porsche dealer, so this was reassuring as well.
There you have it!
Thanks again.