Depends if edges are just dull or damaged. One, two pass cycle on the diamond wheel can sharpen nicely. More might be needed if there's deep damage. This is one area over the Sparx where the SP has an advantage, with Sparx you could burn up a lot of wheel life trying to get out damage. Yes, they have a so-called crossgrind wheel to remove deep nicks, but it takes out all the edges so even when the finishing wheel is put back on, you'll have to do many passes to get the hollow back in, so either way, lot's of wheel use. The Sparkx wheels are their weak link.