http://www.j-thomas.com/Catalog/035.htm I was looking at edger blades in the J. Thomas online catalog and see that they have both sharpened and unsharpened blades available. Stupid question, but why go with one over the other? I've seen some blades with a slight bevel along the edge before, is that considered a sharpened blade? I'd be inclined to go with the sharpened blade just because it's thicker (.155" vs. .095"). What do you think?