I'd been struggling with my Kartboy purchase for a while, ... it didn't quite seem like it was a short enough through. The reason for that, was that after about a day of having it in, it just seemed right, ... like it was supposed to be that short (which you would expect it to be too short for a while, not just right).
The benefit over the B&M that has got me liking the kartboy shifter more is the fact that the kartboy shifter is 1" shorter than the B&M. I really like where it sits height wise. If I had it to do over again, I'm not sure what I would purchase, the single piece bushing the B&M has is nice, but the price of the Kartboy offsets that detail.
P.S. Yes, ... I meant that the Kartboy is 7% longer THAN the B&M, not longer than stock. The Kartboy reduces throws by 35% (on a P5), and the B&M reduces it by 42%.