Saves you time and money for tuning your edges. The file is easily replaced once you wear it out. I've used my file for 2 seasons and it still has a lot of life left. The file is also reversible depending on how much angle you want. Make sure you file the correct way though, it's directional and has an arrow on it
This is the first edge sharpener that I've bought and used personally. From the little experience that I have it seems to work great. It definitely saves a lot of my by not having to get your board serviced all the time. I would recommend it for anyone looking to start sharpening their own edges.
As far as tools go, this is one of the more simple designed ones, which is a great thing in this case. It's easy enough to sharpen your edges and if you want to detune them you can pop the file out and use it as you want which in my opinion is its best feature. Very simple yet effective tool. A must have if you're going to tune your own boards