I you are using Giardini's paint and like to have better edges I will suggest that you get the primer and the semi dense or dense colorless paint, apply it to the edges before you color them, once you do that you can use the Fileteuse to smooth the paint coats,but also the nice thing about the tool is the creasing detail that produces on the edges and also you can use it to mark the leather before you punch holes.
If you are on a budget get it from Randall campbell, they have a version of the tool that is fare and if you do some research you ca save couple hundred dollars getting the parts someplace else.