Hi Mike!
I use med glass beads for most of my blasting. With med beads on G-10, you have to go at it a bit longer, but for me the med glass beads offer a wider variety of finsihes than I can get with course or fine beads, it all depends on how long you blast the surface. I own a small Snap-On blasting cabinet which seems to work best at around 70psi, pulling 9-11 cfm. Don't worry about splintering G-10, you can do just about anything to it without really messing it up.