Well, as near as I can tell, the only real variation in the 'swept back' grinds is that some prefer a straight wing, and others like a slightly convex grind. I wore one Ellsworth grind down to a nub, and almost got there on the second one. I don't use them at all any more. Mostly I don't find them practical, which is heresy for some. I converted to the 40/40 grind a while back, which is most efficient for the outside of a bowl and any convex shape, and for the inside of a bowl down to the transition area. Then I switch to a BOB (bottom of bowl) grind, which I have several variations of, from 60 to 70 degree bevels and a ) nose shape. The only use I can see for a swept back grind would be for shear scraping, and I prefer to do that with scrapers with burnished burrs. I do all of my sharpening on a platform.
robo hippy