Sounds like a ringing endorsement!

Regarding sharpening a disposable blade -- that was primarily in response to Jeanette's requirement that the tool continues to be useable if all the shops were closed in some sort of catastrophe. I've done it, and it's not hard at all. I used the Spyderco Sharpmaker. Maybe the angle was not the same as the original angle, but the blade worked.

Normally, it's just easier to replace the blade.