Haha, just giving it a try out this season to see how it does. Had a chance to chat with John-Kyle a bit and shoot his stock at the PRS finale and really liked it. A real nice "dead" feeling with none of the vibration of a chassis, seemed like the recoil movement in the scope was over more quickly even though it wasn't as heavy as my weight kitted MPA.
I figured with the whole weight kit issue it would just be cheaper and simpler not to remove material from the stock only to add it back in with brass kits. Less $$, less work, less potential for moving parts, less cracks/crevices for dust to get in. Probably not a huge difference in overall weight once you figure the density difference between Micarta and Brass, I'm guessing less than a lb?