Ordered this to replace my OEM bypass valve and glad I did. Original one was just caked with black grease/soot/carbon/dirt...it was just bad.
After installing the new BPV from Detroit Tuned, I notice a slightly quicker throttle response and a significant reduction in the "YOYO effect" (slowing down, foot off throttle, feels like it speeds up for a second).
I highly recommend this modification as it's (relatively) inexpensive and only takes about three or four hours for someone of low experience to install.