Fabulous stuff Chris! Thanks for taking the time to do this. And damn nice posture too (don't try that at home kids!).
As many, including me, have pointed out here and on Facebook, the PRO arm runs better with the bone angles slightly down from one another. Then on the Facebook discussion, Ron Baldwin pointed out the possibility of testing different spring canisters in the PRO arm at various tensions to see if that makes a difference as well. According to PRO (if I remember correctly), the arm behaves more or less the same regardless of spring configuration and settings, but I bet there is a slight difference in performance. In other words, it would be interesting to run the test with the spring configured where the springs are cranked higher (i.e. four blue springs cranked up verses two black & two blue with less tension). As Chris points out, the PRO arm is so good out of the box, but I wonder if like the G-70X, playing with tuning options changes the test results.
Obviously, both arms are amazing and I don't think this (or any) test is going to make one arm "king." At the end of the day both arms have been used to make extraordinary shots. The Operator brings the talent and picks their tools based on personal preference.