I think it's all a mental game, and if you think an extra mechanical device is going to help you execute your shot better, then it just might.
There are a few justifications for a dropaway rest that I have heard/read. One was vane clearance (which shouldn't be an issue anyway.). Another is that they should be more "forgiving" because it only guides the arrow long enough to establish its path, and should be less susceptible shooter input or form inconsistencies.
However, I have also heard the argument in favor of a limb driven dropaway rest vs a cable driven dropaway rest that directly contradicts that argument and states that a limb activated rest is more accurate because it takes longer to drop. So (aside from using a simpler mechanism) it's better because it guides the arrow through a longer percentage of the release.
So which one is it, and why wouldn't it be better to just have the rest guide the arrow a little bit longer with a fixed rest?
I think it's all of above, and it's none of the above.
Set them up properly, put the bow in a shooting machine, and they will just about put the same arrow repeatedly in the same spot.
Now insert the human factor.
The placebo effect is so powerful that medical studies always have to account for it because the human mind simply believes something is happening, and the body follows suit.
Ever lift weights with a spotter and he/she hovers their hands under the bar without touching it, and all of the sudden the weights felt lighter?
In summation, use whatever you "think" is going to get you the best results, and then focus on executing your shots consistently. If you practice the latter religiously, you will have a made a self-fulfilling prophesy, because the former will not have mattered (assuming you set it up properly and it is functioning properly.)
I use Firenock Aerorest Micro-Adjusts on all my bows. It's a fixed rest, full containment, no cords, no mechanisms, built solid, and it won't wear out in my lifetime. I have no intentions of blaming it for a poorly placed arrow. That responsibility falls on me.
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