Good question gibblet.

Yes, it's main purpose is for tuning the rest. I've always usedpaper tuning anddecided to give it a shot after reading an article. I found it more enjoyable and much easier to do than paper. For one you find out faster if the changes you are making in your rest are working. The second reason is that you get to practice at alonger range.

It also adds to practice in the fact that you have to sight in your bow dead on at a small target. and by dead onI mean you are hitting an eraser sized target. So, you have to concentrate on a very small target.I think sometimes when shooting at longer distances people sometimes shoot at a large target area, not a precise point. this sort of tuning now makes me focus on small spots like previous arrow holes as targets instead of the whole ring.

I was not indicating that it replaces any of the things you have listed. It's not a way to set gaps or for trajectory charting.I use the PC programs for the same reasons you are stating. I actually used the PC program to figure out the closerange to stand for French tuning. Since I know there is a 53 yd marker on my rangeI just plugged in that as my aim point in OnTarget and it shows me the range to stand close.