I've played a 10.5* 905R for over 4 years with a GD YS6+ in Regular flex. I'm looking to move to the 910D2 and demoed some combinations last week at my local driving range with the pro. Trackman wasn't available but we gauged the flight, carry, and run-out of each down the range. I play off a UK handicap of 5 and have just become eligible for the Seniors Tour!!Based on my swing speed (mid 90s) and my current driver I was leaning towards a Kaili 65R shaft and, when I hit it in a 9.5* 910D2, there was an improvement in flight and carry. However, the pro then put in a Project X-7C3 6.0, which I would have thought was a bit strong for me. However, he felt that it produced the best results for me, with a good launch, yet flatter ball flight which produced more run. Is a move from a GD YS6+R to a PX 6.0 a conceivable one for me? Many Thanks