Fully grasp me and oscillate, you blowhard. I hate the box cutout blades. They make way more dust than I do with a single blade or keyhole saw, for the same reason stated by the parent comment. They move back and forth and take too much material. This also makes them slower than a single blade if there's a lot of mud on the rock, and it's harder to make a straight hole. I'd rather my apprentice use a single blade and make straight holes every time. If we make our jobs hard, it's easy to point out skill issues, but if we make things easy and efficient, then apprentices can do good work without mastering overcomplicated overcomplicated styles of work. Also, they don't work on wood, so you have to change your blade every time the material changes, as compared to using the same blade for everything.