Few days ago I've tried retrofitting comfort headrest from Audi in my Leon, because they have two axis regulation. Unfortunately they does not engage with the guides (notches on legs are in different position) and whole headrest slides freely up and down. I've got plans to cut notches by myself to resolve that issue but we will see.
Other than that the comfort increased drastically. Finally I am able to, well... rest my head while driving
You can click on the image to hear very satisfying "clicks" when position is adjusted.