I agonized over which sharpening system to buy for my chisels, planes and knives and ended up pulling the trigger on this set; I am very happy with my purchase. Sharpening these "stones" is very easy and I found the blue (coarse) stone to be my favorite because it allowed me to quickly reuse the blades. A green (fine) stone will make your tools sharp, but you'll need a polishing paste and snare to bring your blades to a brilliant shine. There are two things I don't like about these diamond stones (they aren't big enough to justify removing the star): - I wish the stones were a bit wider. My most used plane (#4) is wider than the stone, so I have to sharpen it at an angle. see photo. The stones don't fit tightly in the wooden case, so you have to remove the stones to sharpen anything accurately. I think there is a gap of about 1/16" - 1/8" on each side of the stone.