Just got done sharpening, looks better than I could ever do with a file. The 'hook' is adjustable, you have to tinker with the height to get it right. Once you get it once it's easy, just a matter of playing with the first tooth and learning where to set it.
Pros-
The angle is 100% perfect. I used to think I was good with a file
Speed. Not scientific I know, but it takes me 3 beers to sharpen with a file. Counting the learning curve I had 1/2 a beer left.
Sharpness- It feels sharper with the finger test
Ease of use- even a drunk amature can do it
Very well built
I don't think the cutter will ever wear out. We abuse bits of the same design at work and they last a really long time. I've never actually worn one out, but I've wedged them in things while hooked to a die grinder and broken them.
Cons-
-The cutter bit, while being very hard steel, is guided by aluminum and is a little bit sloppy. It is good enough right now, but the guide might start to show wear after heavy use.
-Carrying case, while well made, is made in china. So is most of the stuff you buy though.
-If the cutters were a little bit longer and went to a sharper point they would work better. If you have a nick in a tooth you have to sharpen, then pull the cutter out, move the adjustment knob, and sharpen again.
-If your bar is worn the teeth will have some side play. There is a knob to put pressure on the tooth from one side, but some way to sandwich the tooth in would be nice.
-A guide for the rakers would be nice.
Neutral-
-No bottle opener. Not a big deal at all, but I needed one at the time.
-Speed. You'll get done quicker and not have a good excuse to be downstairs anymore.
-Price is expensive, but worth it.
-Don't tell your friends you have one, they'll keep you busy
Overall, I would buy it again for sure. I used to think I was good with a file until I used this and really saw how bad my angles were and how dull the chain actually was. I have some logs in the woods ready to cut right now, and looking at the chain I'm pretty confident it's going to be a big improvement.