First, I've never used this one. I've seen it in Rockler and it looks well built. I have one of Paul H's drilling jig and PSI's new spring loaded press. I love them both.
One thing that jumps out at me about the Rockler one is the sacrificial blank to prevent blowouts. I hate it. It MUST be a particular size, and you can't move it a bit to get a new flat spot. When you drill through on your first blank (especially if it's a larger bit), your sacrificial blank is shot and if you don't replace it you'll blow the next blank out. You better cut a few hundred of those sacrificial blanks out. It's a "one and done" design.
With Paul's, I just cut several pieces of scrap plywood the correct width for his design, didn't care as much about the length (around a foot is OK) and with each new blank drilled, I just move the plywood to a new flat spot. Zero blowouts, with very little hassle. When I cut up the one side of my plywood (20-30 blanks worth) I just turn it over and have a new flat surface. Now, if you go all the way through your sacrificial plywood, you have another problem, but I go slow, cleanout often, and can see the color change and texture change easily enough.
That Rockler sacrificial blank deal would be a non-starter for me. And for those not fortunate enough to get one of Paul's, find one where you can put a piece of wood you can move underneath it. Someone wasn't thinking when they came up with that design. Or never tested it.
Dale