I use the Diamani Blueboard 63 stiff in my driver and 3 wood. I hit my driver around 210 and with a tight little draw have hit many 230-260 yard drives. I'm 68 and I consider myself a short hitter and my handicap is low. I just shot a 76 and a 74 and not from senior tees.
I'm always told by fitters I need a regular flex. With a nice smooth shaft like the original Diamana, I hit the ball much straighter and as long, if not longer than a regular flex. I do use a regular flex in my 9,7,5, and 3 woods in the Diamana Redboard and every shaft is tipped appropriately. I hit these shafts more consistently than anything I have tried. I've hit some of the newer $200-$300 and they aren't better. Maybe the newest Fujikura is good, but the early ones aren't nearly as good as the original Diamana. I've used these shafts since the first came out and they are as good now as they were when new. My driver is the Ping G400max and my fairway woods are the original Cobra SZ heads and they are amazing. I can't imagine I can hit a ball any better than with these woods with these Redboard shafts.