I've not got a Q7 yet. I'm searching for a 4.2tdi at the moment. My current audi family is a B5 RS4 and an A3 cabriolet. Doug and his team have done a lot of work on the RS over the years.
Not asked for figures on a 3 litre, but the 4.2 should see between 390-420 bhp depending on which model engine it is. The later models make more bhp.
I did enquire about an A6 3ltr tdi remap and Doug said around 310ps and 700nm if that helps