OK, a little about shafts, you're using the same brand shaft, so R and S should make a difference. Going from one brand to another.....you just don't know.

Lets say you find a mid $$$ shaft that works great for you, well you can find a low $$$ shaft that works just as well..........but finding another low $$$ shaft that performs the same may be a long search, to find a mid $$$ shaft that performs the same you just buy the same shaft.  The high $$$ shafts are basically mid $$$ shafts but they know someone will pay the high $$$.

So you have some consistent shafts, R vs S

Every shaft has a range of bend where it will perform the best. R will bend easier than S.  If you don't bend the shaft enough you will lose power, if you bend it too much you will lose power per unit of effort put into the swing........at this point using a stiffer shaft you will gain distance.

So with a driver swing speed(DSS) of 80mph, you will hit the R farther because you don't bend the S enough.

At DSS of 90, they will probably be the same.

at DSS of 100 you will hit the stiff farther because you bend the R too much.

Lets say you hit both about the same power wise. But you can't control the R as well as the S. That is because of swing flaws.....EVERYONE has swing flaws, the worse your swing flaws the stiffer shaft you need. Or in most cases simply a heavier shaft will calm your swing down and make it smoother, which would be better than going to a stiffer shaft.

Heavier weight, higher bend point, stiffer tip, are things that make a shaft feel stiffer. They do make minor differences in ball flight, but you should use these for feel. For example DG S300 feels too stiff, DGR300 feels too soft, then try TT Lite XL Stiff or Dynalite stiff or DG high launch S300.

The characteristics of the shaft you use is mostly about feel.

Thank you that is very good insight.  I actually went with a S NV shaft in two 909Hs.  I am waiting for them to be made and delivered.

I would wait for the 910's.  It's a wait, but it's worth it.  I'm counting the days until its release.

I did not wait for the 910's since I already have the 909 d3 driver and 909 f2's 3 and 5 woods. I got a stiff adila voodoo shaft 21 degree hybrid to replace my 3 iron and I love it. Much more constient with it than the 3 iron. I didnt wait since I love the 909's I figured I would keep the set the same. In years to come I maybe upgrading to 916's or something, lol. Have fun with your choice though.