I run into to many people that have large collections of items such as tools, cameras, guitars and such but couldn't use them properly. I have a large collection of SR's but only a few stones as I have mentioned in previous posts and I do quite well with those. I can understand having a large number of different screw drivers because not all screws are created equally, maybe if I tried a few of the newer synthetic stones I might change my tune but I have never found a knife or razor that I could not put an edge to. Now having said that, I do have a Norton 4/8K and 12K on the way to try out.