Tuning 2.8L aero

Hello, when I see myself so on the net I do not see so many offers for this engine. Hirsch, BSR and a few chip tuners unknown to me. If I compare the prices between BSR and Hirsch as in most cases a par Euro. if I look at the performance however also, in a positive sense here for BSR. Does someone experience with the tuning from 2.8 aero? Greeting Michael