Review on Dremel 561 Multipurpose Cutting Bit, Medium: Versatile Tool for Precise and Efficient Cutting by Trey Samuels

Works as it should. My only concern is that it tends to burn wood as it cuts. I use them primarily to cut 6 foot diameter circles out of 3/4 inch thick plywood. I always have to sand the inside of the cut afterwards, but they consistently cut (even if they burn the wood a bit). I can usually use one of these blades for about 4-6 holes before having to replace it. This works very well for the cost as far as I understand it. If you were using them on drywall I would imagine you could make 100 cuts before replacing them.