I have not used one, but i looked at it in the store. At first glance it seemed like a good money saver to me, however I didnt believe it would be worth the money based on my experience on buying the chainsaw sharpener. On the chainsaw sharpener , it seemed to have wiggle room when moving the motor up and down and there was no way to adjust it to make it tight. i checked for play on the circular carbide sharpener and found that the arm lock and sliding movement to move blade to be sharpened also had too much wiggle room for my taste. looked like a waste of money. Also when i tried to move the blade to pretend to move to next teeth to sharpen, i was suprised on how easy it would be to cut myself since there was too much friction and no gaurds to protect my fingers. IMHO - its not worth it. If carbide is supposed to be very flat and cant have angles on it to cut, what are the chances HF will remove those perfect flat surfaces ? Its cheaper just to buy new blades then it is to buy this tool.