I've been considering the C721 driver and play a few other Tour Edge clubs that are as good or better than major brands for me. I've watched a few good reviews on youtube. Anyway, sometimes certain clubs just won't work for us no matter how hard we try. I'll buy a different shaft just to make sure that's not the problem. I usually go the inexpensive route like Diamond Tour golf where I've bought several cheaper shafts just to see if that's the problem...God luck!
I really don't think the proV1 is for you since they're much firmer than what you've been playing. I'm 73 and have only been playing for 8 years. Started out playing most anything soft, then saw the MGS golf ball tests and switched to the ProV1. Played them for a couple years and lost just as many of them as the softer balls and saw no change in distance. A few months ago tried the Callaway Supersofts and within a few games I hit my longest drive ever of 240 yards! I'm sticking with these!