I have a Slay/R, Red/Black, and a recently drilled Power Groove. Not much play with the Slay/R yet, but I sure like the Red/Black for Medium/Light & light patterns - especially a house shot that's breaking down. As long as there's a tiny bit of head head oil that can be chased to the left, it keeps you in play. With my limited play on the Slay/R, I don't think it has the back end to get in real deep. Time will tell. I'm probably going to drill up another Slay/R with a pin under bridge type layout and use it as a "Track Jammer" and 'Twig' ball, and keep the Red/Black & Power Groove for shots that require a deep alignment or lots of swing. The Red/Black and Chrome/Yellow Power Groove has a much higher RG than either the M-R/B or the Slay/R, and it gets down the lane pretty easy and smooth.