Wife got me one of these for my birthday. Any vet that has seen my mushroom stump thread over in the DIY forum knows i'm a decent hand filer...one ONE side. . You can see the "correction" cuts on those stumps I had to make as the bar curved. As I sharpened today, at first the stone fit like a glove and went easy and quick. Then i flipped the saw around and could only sharpen the top 1/8 inch or so of about half the cutters on that side.This was due to my hand filing inequalities, I'm sure. Tried to go real light as I've read on here,and sharpened what I could. Chain cut suprisingly well but curved a bit still. Think i can fix cutters with repeated sharpening and fix the tooth shape. Pros - -Worked well at first blush, very quick. 3 minutes a side on an 18" full comp. Sorry. Just wanted to type "full comp" for once describing one of my chains...but I digress. -easy to use after set up. -Cheap, at 30 bucks, readily available for test drive at Lowe's. -has a 12 V cigarette hookup or alligator clips for portability. - different sized stones -easy to line up large angle markings Cons- -has a 12 V cigarette hookup or alligator clips....ONLY. No standard cord = No sharpening on the coffee table while I watch the Pens beat the Caps. - chuck and little wrench combo has an "erector set" vibe. Could see some struggling with it. I'm still 5 years out from bifocals, I hope. This will suck then. - Cheap, at 30 bucks. some online reviews say it falls apart, others say it's solid. What say ye out there? Thoughtful gift from the missus, so i will cook it till it's dead.