Quick report, I yanked out the big black intake resonator box over the weekend, not the two tube section and the butterfly valve but just the lower box portion (man, that thing is huge). I plugged the pipe leading straight down to the box at the very top to smooth out the airflow so all air is still being drawn through the tubes with the two-stage valve still in place.
The biggest difference I notice is from 2k-4k, it seems to rev more freely and has a slightly increased sound. At high RPMs it develops a bit of a throbbing sound which is probably what they were trying to reduce by including it to begin with. It's not too much louder, I like it.
KrautLude