After using the precision sharpener for a while you get the hang of it (like learning anything new I guess). What I like is the fact that you can get the chain back fairly close to factory specs as far as the angles.
I could never be that accurate doing it freehand although I can touch up the cutters. The only thing that you have to juggle with is setting up the depth of the file so the top of the cutter is 20% below the diameter of the file (this is done by eyeball with an adjustment screw). The difference between 20%-25%-30%, etc. is the toughtest part for me to gage. I will give it a couple licks and if I'm getting too much of a hook I raise the file up a hair.
I'm thinking the side of the cutter is a little more important than the top as far as sharpness. A slight hook will probably slow things down a bit. Any thoughts? I'd like to see a real close up movie in slow motion of a cutter actually doing it's cutting. I'd like to see this for different types of wood too.
The three sisters (dogs) help me keeping the woods behing my house free of critters when I'm cutting. They hear a chainsaw, they come running. They enjoy toying with the smaller limbs, getting into big tug-of-wars. They are big talkers and like to get into barking contests with the foxes that live in the area. Shut UP!!!