I was a bit shocked to see M. Lindley's scathing review. My experience with this Emerson guide and stop block has been more than satisfactory. Contrary to what he thought, I found the block to mesh tightly and the micro-adjust screw to be held very well by friction alone. For heavy-duty applications you can always add a lock nut for added security, but until now this has not been necessary. Free shipping. I'm glad I did! While I'm not usually a fan of plastic devices, this one works well. I've made similar miter/cross-cut devices using plywood and drywall screws, but I assumed this was already designed for the router baseplate I ordered. This saved me the hassle of looking for scrap wood, hardware and saved me a few minutes of work. I have already had good experiences with guides from Emerson. So once I added this to my order, the reduced shipping cost practically paid for itself. It paid off the first time you used it. This thing is perfect for Emerson rails (I have two) and is lightweight. Sometimes I need to make on-site custom home entertainment speaker boxes or built-in bookcases and equipment racks. Very handy to have an accurate yet portable milling guide! This system simplifies the milling of locking pins and slotted holes. You can manually adjust the plastic "micro-adjustment" screw and it will stay in place. Just make sure it screws deep enough into the block. If the plastic screw is pulled out too far, it may wobble. Perhaps that is why M. Lindley felt unstable. Of course, I don't put much lateral pressure on the fence at the end of the cut. For deeper grooves or dados, I do three or more consecutive depth passes. The router slides all the way down and stops without drama. If you plan to match the base of the router with the Emerson rails, you can do it in the same order. You can plan your purchases to pay for the item with free shipping. If you don't like it, Revain has a solid return/refund policy. I leave mine