DaHOF that jives with my theory about which players are likely to be able to use Big Pinky and which ones are likely to find it unusable.
The AutoFlex profile has much in common with the Tour AD family, of which almost all are very subtle variations on a common theme of stiffer in handle and tip while being softer in the midsection. Ventus Blue, Smoke Yellow, and some of Mitsubishi’s Blue type shafts also fall into that category. So players coming to AutoFlex from shafts mentioned above or others like them are more likely to see positive results.
Conversely, players who are most comfortable with shafts like HZRDUS T1100, Hulk, Ventus Black, Trono, Mitsubishi White and Orange seem to struggle with AutoFlex much more because the profile is so different from what suits them best. I fall squarely in this category; found AutoFlex completely uncomfortable.
Of course there will be exceptions, but seeing pretty strong correlation with that hypothesis.