Economical and relatively easy to uselike the item does the jobI bought this sharpener so I could do a mass sharpening after a week of cutting. I found that this unit doesn't come close to outperforming a file, not even close. It only affects the top edge, and even setup perfectly misses out on key sharpening details making the finished product still to dull to be an efficient method of honing your chains. It only takes a few minutes longer to sharpen a chain by hand, and the results are what everyone wishes for..a chain that cuts like it's brand spanking new. The Chicago Electric sharpener is innovative..but comes up short against it's objective. I'm going to mod it and make a hand grinder for odd jobs.There always room for improvement.The platform can be better (you can't really get it tight on the deck or table in order for it to be and secure with no movement).Better base and longer better screws.A bit of a learning curve on using this, but there are many YouTube videos that really help. This has made a huge difference in my wood cutting, like cutting through butter now, and it’s saving me a LOT of money - sharpened 6 chains now, so it’s paid for itself already!Easy use and adjustment s fast from chain to chainFirst one I got was broken but leave it up to Amazon it was quickly returned without any problem. Second one I got is missing a spring that is really necessary at the sharpening stage. The spring goes under a plate the holds the blade tight. Manual specs say it suppose to have three springs but only two were put in. Company (Northern Tools) said that they don't have parts for this sharpener and to return it to their store. Also said that they can't guarantee a product coming from a third party because it could have been returned broken. I took it apart and found a spring that would work. Big difference and it works very good. Three stars because part was missing.sharpen chainsaws