Thinking of Getting JHM Tune

Hello.

I am considering getting the JHM tune for my 2008 S6. I have done a search here and there is quite a lot of positive opinions on the tune.

This tune will be going on a stock S6. I may later get the JHM exhaust.

Anything in particular I need to be aware of before I get the tune? Also, will the tune also reprogram the transmission shifting?

Thanks.