Has anyone used the Circular Knife Sharpener?

I'm assuming you mean the paper wheel sharpening system??? If so, I personally use mine quite a bit. I'm able to get a real sharp edge on my knifes. I also use it to touch up my cutting edge on my sewing needles. For me I personally think it was worth the money. But what works for one doesn't necessarily work for others. Just for me to touch up my sewing needles keeping the cutting edges sharp was worth it for me.

 

Worth it's weight in gold.... IMO.
I have 2.

 

I believe they are talking about the shaper for the round knife sold by research manikins.
I cant yes or no for I have no need of it. If I hit a bullet and other crap I just rehone it with a grinder stone from my dermal kit and go from there. I wear my blades down to nothing lol

 

Oh Ok.. Yea I wear my down to nothing myself. I only swap when they quit cutting. I bet the lip is less than a 32nd.. Lol.. Im a tight wad..