This tool does what it says it will do in a great way. It's easy to use and fast setup and to work with. The base plate is easy to install and provides a bushing and small tool to align it correctly to your router. At first, I didn't understand why it was needed but once you try to install the base plate that comes with it, you understand - if the bit and base plate are not centered correctly, the scale will be inaccurate. The base plate is universal and because of the way the holes are made (they're made to fit just about any router out there), they won't centre on your router like the factory base plate that comes with your router hence the tool to centre it correctly. Takes only a few minutes to setup. The router bit that comes with it is good and could possibly be replaced once it is no longer sharp. (I'm not sure if I would try to get it sharpened but we'll see later...) The drill bit to make the centre hole is also perfect for the provided pivot and the screw that comes with it. You don't get the feel that the hole is too big or too small, it fits perfectly. If you don't want the hole to show through, make sure you drill from underneath your piece of wood (ie: if your piece has a side you would prefer be on top for example) and stop before you punch through.
All in all, a good tool at a great price. Highly recommend you get this to make perfect circles. I used to do them by hand and then sand them down but this is way better. The results are excellent and require little or no sanding.