Seniors flex vs Regular flex Shafts

What differences are there between these 2 types of shaft?

One of my playing partners is well into his 60's now and he struggles to get his irons high and long now. I was going to suggest he changed his clubs or shafts and get a seniors flex shaft. It's my (possibly misguided) belief is that they stiffer the shaft the more penetrating the ball flight will be. Is this correct?

Cheers

I think the senior flex shafts are more whippy so they generate more club head speed without needing the full back swing - those slazenger big eeeze woks on a stick have them..

Could be wrong though best wait for a reply from one of our old seasoned pro's  - you there Tony,.

Graham, some people are very strong still into their sixties and even beyond,personally I now find that I am pretty weak and need the help of the soft regular shafts.

I have just been fitted for my old blades and the stiff shafts are coming out and True Temper very light steel shafts with a flex bordering on the bottom of regular and the top of Senior with a softer tip. I am hoping that these will do the trick for me.

I was discussing this today with my local pro. He was saying to much emphasis is put on the flex of the shaft and they key element is the load on the shaft. I've been using Wilsons with a regular steel shaft but I've now sold them and gone back to my original Ram Irons with a regular graphite shaft and I have to say today I was hitting them better than ever. I was gonna buy some new irons but I may just stick to my Rams for the time being. I can't afford new clubs at the moment and was just looking at 2nd hand, so I may just wait now.

Sanders that was a very inetersting article you linked to ^^^^