Has anyone used this hammer & trigger jig before?  It looks like it would be great for doing AR trigger work, but I'd like to hear if anyone has any input, or if they can recommend something better.

http://www.brownells.com/userdocs/products/p_080000070_1.jpg

I use 1000grit paper and "wet sand" the trigger face and hammer notch to take off the tooling cut marks. I have granite countertops, so i pit a drop of oil on the paper and make slow delebrite figure8's and check the surface very frequently. To get the little ass grove in the hammer, i take a few inch long strip of 1000grit paper and fold it length wise on something hard and flat. In my case i used an old license plate off one of my deceased vehicles. Just fold the paper over the long side of the license plate and be careful not to change the angles.  Afterthe tool marks are gone, i bust out the mother mag polish and the drrrrrrrremel!! Use a polishing cloth wheel with the mothers mag compound. Also you can buy a tap, and tap the rsat of the grip screw hole in the lower reciever; and install a setscrew which takes out the play called"take up" or first stage. Sometimes have to take a grinding wheel and chop a notch out of the back top side of the hammer to clear the pin....  I can knock out a trigger in about 10 or 15 mins now. All my buddies love my triggers and end up giving in and asking me to do theirs. Be careful, go slow and check it often. Youll have great results that way. Good luck man!!!! read, read, and read more. I dont think that you need that trigger jig. Iv done close to a dozen trigger jobs with the above method. Several thousand rounds down the pipe of my AR's and not a single hicup

that looks like a good marketing product

How to do it wasn't my issue at all. I've done a few and they've turned out well. My issues were a) being able to test it without installing and uninstalling repeatedly because I'm a perfectionist, and b) being able to actually see how much engagement there is.

I also liked the idea that the jig attaches to the lower you're doing the trigger for so the distances aren't just a standardized estimate.

No but you asked if anyone knows something better..which is what he was saying to you

I have one and it works good, Because the pins go through the recv. you get a good view of engagement.