I dig it. But...I run 5.29's and 35's, and NVH is way down at upper RPM, and it is shifting smoother at higher RPM's. It doesn't change the world, it's just enough with my *light* 80 that I'm in the left hand lane passing up Monument Hill vs. the right hand lane bogging. The rig feels right now, not supercharged or anything, but just more ready to pull, without the NVH, rather than always on that edge of bogging down, even with the low gears. That's a subtle change, but one for me that increases driving pleasure and makes me more willing to hit 3,500-3,700 RPM for brief stretches at 70 mph in 3rd vs. slowing down to that higher pass crawl.
IMO, very well spent $300...but...my 80 is a bit atypical (gear ratio/tire size, weight) so my experience may be outside the statistical norm. I do carry my whole family of six on long trips, and I'm pretty sensitive to NVH issues despite my tire choices
, so this is a mod that hits home for me in the dual use arena.