Well, just got and installed the NAP Quiktune Sizzor. Had previously gotten the Anchor Sight (ArcheryInnovations.com) instead of a peep. Took a bit of tinkering to get everything where it needed to be. The Sizzor sits a little higher that my previous rest so had to bump my nocking point up a little to paper tune. Because of this, I had to raise the sight pins to compensate, and then the Anchor Sight kept me from seeing my 20 yard pin, so I had to move the Anchor Sight and in up and so had to readjust to get it to line up. Lets just say shooting fatigue was starting to set in a little after tuning and sighting in. Despite this, my field tip groups (when my form was good, and didn't grab the bow with the shot because of the fatigue) was tight out to 80 yards. I was quite impressed.
The setup instructions for the Sizzor said draw the bow and let the string go through the rest (string is adjustable with tightening a screw) and then let down and pull string tight another 1/4 to 1/2 inch. I was at 1/2 an inch before the hammer would completely deploy the rest on my Mathews Z7 (I think there is not a whole lot of movement in the downward cable compared to some other bows) and I probably ended up with more like 3/4-1 inch more slack taken up in the tuning process. There's a post from 2009 that said they were having some trouble with left or right tears (I was getting tears to the right) that went away when I took up that bit of slack. That would essentially leave the arrow guided longer before the rest "falls away" and then I was shooting bullet holes. I'm thinking this will also help with my problem I had with my last rest with broadhead tuning having the arrow guided longer before the rest falls away. That is still to be determined, but I will say that my field tips are grouping a lot tighter.
Still really love the Anchor Sight, and I think I am going to really like the Quiktune Sizzor. I'll update when I start shooting the broadheads. Only downside I have right now is that I have to manually reset the Quiktune Sizzor between shots.