We use the Hole Pro adjustable hole cutters a lot and the low speed setting is perfect for good cutting speed and having enough power to cut 8-1/4" holes in TJI or plywood. The middle speed we have learned makes for smoother cutting with hole saws though we have switched to using Blue Boar TCT hole cutters 90% of the time. We can easily cut 6" holes in inch thick plywood with an 18 volt cordless and the very efficient Blue Boar hole cutters.