I've been using mine for a while now. It really needs a taller axle ratio. I'm still using it with my 3.73 Volvo rear end, and it's 6 closely spaced gears, and it spins the motor more than it needs to (it's a turbo LS) on the highway. I'm planning on putting a Ford 8.8 axle in with a ratio close to 3:1(ish).
Other slight nitpicks:
Specific to my install (LS/Camaro T56 clutch setup) - using the Volvo 260 hydro clutch master with the Camaro T56 hydraulic throwout bearing doesn't work well. Even though the Volvo master cylinder bore diameter matches the Camaro master cylinder. It's a very stiff pedal, and the engagement point is very narrow. I need to go down in master cylinder bore a bit, get less pedal effort and more pedal travel.
The CBF Performance top-mount shifter has some issues. In general, it's got nice short throws, feels nice. But I'm using an offset mount on the shifter lever which reaches back diagonally to center the shifter in the 240 shifter location. This puts a little twist into the shifter mechanism when rowing the gears, and that helps amplify a little bit of slop in the shifter mechanism. So it's 6 gears in a pretty small space, with a bit of slop added, it's just not as nice as it should be. And the shifter retention/detents aren't quite strong enough - it will tend to pop out of gear in some gears (like 5th/6th). Might be due to the rubber Volvo shifter boot being too springy (I need to replace it with something less restrictive), but partly just the detents being to soft. This is something that the CBF kit replaced - the detents work against their new part.