I have a 910D3 8.5 turned down to 7.75 with the Devotion 6 shaft 06 flex. I got fitted for this setup for the super low launch and low spin of the shaft, which works out perfectly if i barely try to swing. Im having problems trying to get the ball to carry further and roll out. When i swing hard the ball balloons into the air and falls like some one dropped it out of a helicopter. Ive been on a machine and my distances when i swing easy are 270 to 290 carry with about 30 yards of roll but when i swing hard the carry goes up to about 310 to 330 but the spin goes well over 3000 rpms sometimes over 4000 with a club head speed of 120-122 and a ball launch speed of about 175-180, which is only about a 10 yard gain of a 110 mph swing with 1800 rpms of spin and a launch speed of 165. Im wondering if maybe the shaft it too stiff or not stiff enough i had the shaft stiffness rated and it was past the charts that my pro had(289 at 45 inches, whatever that means) which makes me think maybe the shaft is too stiff. Maybe someone can help me this is the first club ive ever had fitted. I got all the numbers from the swing computer but it seems to be very accurate to what happens on the course. my launch angle is about 13.2, the computer said optimal was 12.7 with optimal spin at about 1900