I seem to be hearing this issue more and more from amateur golfers. I too have been surprised by the results of different shaft weights, flexes etc. I have always used a S shaft with a low lofted club for about 20years. Mostly hitting high shots with all my clubs. Recently I noticed some loss in distance and accuracy. Looking for a rescue club one day at the course, I grabbed a Ping 17*, but the Pro only had an R shaft on it. I played 9 holes with it, and hit the living tar out of it, dead straight. Got back inside, and ordered the same club, in an S. You can only guess where this is going. Lost 10 yards and was all over the course with the S shaft. Pro tells me its not so much about swing speed as much as my tempo, which is long and lazy. Traded in 9.5 driver with S shaft for 10.5 R shaft and I cannot believe the difference in accuracy and distance, about 20 yards avg longer. Go get tested and fitted, worth the time and money before thinking
or guessing which club is best for you.