I can go through several chains in one day now and not have to make a trip to the hardware store to get the chains sharpened. The product is as good as advertised and maybe better! I have had it for several months now and sharpend even the worst chains to use on stumps. Very easy to set up and even easier to use. I can't think of anything bad to say. I probably spent $60 - $100 last year on new chains and sharpening (mostly sharpening). Then I tried sharping using files. . .effective but very time intensive. I'm done with a chain now in 2 - 3 mins.