I just purchased the AFE St II also, will install once I get back, I also got the the throttle body spacer, and the Sprint booster, I'm pretty sure it will be more responsive than stock with this minor set-up as I have the booster on my 04 500+WHP M3 and do feel the difference even if it has it's own sport button. NOT more power but better acceleration and response! Later will do a catch can so all that gunk won't enter the engine and get clean air.
Don't worry about the negativity, or un-motivational responses, It's your car, your money, so do what ever you want with it!!
By the way! Great work on your engine!!