Its a commonly held opinion amongst club fitters that every player should play the lightest club they can control. As far as I remember, the SL shafts are about 10-12 grams lighter. If you have no problems with the lighter shaft its a win win situation. Lighter weight allows greater clubhead speed (more distance and height) and lower fatigue towards the end of a round (less weight lifted through the round, just like a runner and lightened shoes).

Get your hands on a couple of demo clubs with the SL shafts and compare them to your own.

D.