The original one I used was a Fiskars that was the small dia. They worked good, but for cutting thick stuff like backed foam padding we used in packing house equipment it was too small. It also turned out to be too small for clearing the jig guides I use for cutting narrow pieces of that chap leather. So the Olfa is the only way to go. I use it almost everyday for cutting leather, shipping labels, and for fabricating custom shipping boxes. My one attempt at sharpening them by hand was pretty much a disaster ending up kind of folding over the edge and making it useless. I've yet to try something I saw here on HMT where he used the back of a sanding belt as a strop.

The two main sharpeners for rotary blades on Amazon have very mixed reviews, like 5 stars and one star with very little between. I think it's mostly if someone is used to using machines or not, if that makes sense.