Needs to be integrated into a complete managment system to get any real benefits apart from the bling factor.

Mapped throttle position based on RPM/LOAD/THROTTLE DEMAND.
Main advantage is emmisions and can aid turbo spool up.
Ultimately , at wide open throttle. its like any other throttle !!!

Need multiple 3 dimensional maps to do it right - probally a bitch to set up and get right.

Have looked into doing this myself on my S8 ecu.

Just waiting for my mechanical wizard chap to sort out the oily bits then its
time to write some software.