There is an old timer at my pool hall that told me why they used ivory back in the day. He said it's because that was the only material that would flex with the wood in the varying climates, and because it's a natural material.
Me personally, ivory ferrules are all I will play with. In terms of deflection, there was an adjustment period for me, but in reality, deflection is all in your head. The human capacity for learning and performance surpasses the need for LD technology you see today. You have to be experienced enough to know and understand how to enjoy the hit of a genuine maple shaft with an ivory ferrule and still play a good game of pool with absolutely no worries about deflection.....
There is something wonderful about ivory, being a natural material, and it looks great. To me, it's one of those things that can't be explained. If I were to put one word out there, I would say Ivory is, "J U I C Y"...... You can compare it to phenolic, but that to me is like comparing a fiberglass shaft to a maple shaft. There are properties ivory has that can't be compared just in terms of hit. Natural materials like wood and ivory have been used to show off an artist's skill since the beginning of time. Those who know about art will pay to have the nicer materials and among those materials, ivory ranks at the top.