I have used one since I started in the hobby in 2006. I rarely use anything else. When they released a left handed one, I bought it immediately. If I do use carbide insert tools for heavy, rapid metal removal, I finish with the Diamond tool. I have ground tool bits with various radii, for, e.g., loco wheel root radii. I can't recommend it highly enough. Apart from the annoying loose washed under the retaining cap screw, I find the sharpening jig fine.