For what its worth,I'm greatly interested in the tuning debate.
Can it turn a half MOA into a quarter MOA or better...?
I'm not an F-class or bench-rest shooter and mostly shoot at my club to 500 meters.
I do demand 1/2 inch accuracy out of my rifle to that distance to feel competitive and not loose due to the rifle ammo combo.
I had my gunsmith ( he is on this forum, well known and respected) chamber two barrels for me last year and when I asked him about if tuners work, he said it depends.
He emphasized that you must have a very good base tune before you start to adjust the tuner to see if it helps .
I asked him to install a tuner on one. I only had one set of test so far and it definitely changes point of impact, maybe improves grouping somewhat. I need to repeat the test to see if any of that means anything.
What I'm saying is that first you need a good rifle load combination that shoots, than a good trusted tuner and be able to shoot accurately to be able to tell the difference....than you deal with the environment...
I feel that by the time you learn enough on your own, testing various conditions , checking group size, point of impact variation, half of your barrel life is gone....