Just so happens that I spotted that sharpener a few weeks ago and bought one online for $22. I have a Spyderco sharpmaker with medium, fine and extra fine stones and until I picked up the Slide Sharp, I used the Spyderco exclusively. I have a Grohmann #3 Boat Knife that I use for most outdoor activities and I thought it was sharp. I ran it a few times through the Slide Sharp and it is now sharper than it has ever been. Took way less time than the Sharpmaker and was really razor sharp! Sure a lot less money than the Sharpmaker too. The only thing I don't like about it is the springs are sort of puny looking and may break down over time. Try one, I think you'll be pleased. Cheers!
No, I am not Bear Grylls, but I stayed at a Holiday Inn Express last night and Bear was there too!