The stiffness of a pole increases exponentially

[arjjon16]

My first thought was that carbon poles return faster. But I land deeper in the pit on the spirit so I know the spirit must be softer. Either way when going with the same brand of pole and you have two or three poles of the same weight you should definitely go by the flex number.

Let me share some info I have learned over the years!
Carbon when laid up in a pole with all the fibers going up the pole will provide you the strongest and stiffest use of the material.
Thus using less glass you have a very light weight implement. However you also have a pole difficult to bend initially and one that will straighten up sometimes too abruptly!
A way to confirm this is to have someone stand to the side of your jumps and watch for two things!
1. Do you lose some take-off energy at the plant does your arms collapse far too much to transfer the energy consistently?
2. At the top of the vault are you actually upside down or more like a flag pole in comparison to the Spirit pole?
You are correct in saying

but in my experience flex number determines the softness or stiffness of a pole as long as we are talking about poles that are made of fiberglass or carbon fiber.

Flex number does determines the softness and the stiffness of a pole within the brand, the new variable is how the carbon is laid up in the pole. People will not be able to use that myth, unless they take into consideration how the pole is made!
a. some carbons are straight carbon fibers to the ENDS OF THE POLE
b. some carbons are straight carbon fibers to the ENDS OF THE POLE and a spiral wrap to dampen the stiffness
c. and others are cloth with carbon strengthening both directions depending on the resin content a carbon pole with layers against each other without a layer of Fiberglas is subject to inner de-laminar failure IDF well known term in the industry to sell more parts such a gold shafts and hockey sticks. I call it built in obsolescence http://www.merriam-webster.com/dictionary/obsolescence to sale more poles.
I watch a man who worked for thermo-flex the red poles and he once broke 10poles at a show on a flex machine and kept laughing "that if they lasted forever we would not sell many! And if the break we sell another pole!" The next year no one wanted to jump on the red pole that got the nick name as the pole that talks to you with a crackle!
The whole thought runs chills up my back. I have and will be making poles that last longer, I want to sell them because they work and never let you down!

Am I out of the thread already? While I'm reading about your post ESSX, I've learned a lot. I'm a student who does a lot of researches online and offline. So it is a big help on me.