Put an Autoflex 505x into a B21 this morning on the range. Couldn't get my Rapsodo to work to see if distance was any different, but I know for a fact the ball was flying straight. I usually play it neutral +2 (9* head), but this shaft launches HIGH. Turned it down to standard loft, but draw setting, to offset opening the face. I also took out the 5g weight and put in a 3g I had laying around. I don't know how much it helps, but I've heard the shaft is sensitive to weight so every gram helps. Just straight balls or tiny fades, over and over. I need to see it on a course or monitor to see if there's any benefits, but so far so good. Don't know if it will beat out my Kinetixx, but I'm going to give it a go.