When done correctly, pretty much any method of conditioning will work.
IB is no different.
I was skeptic of Iron Hand training so I took it up and it cleared my doubts.
When I decided to try IB work I realized that the time needed was something that I didn't have available.
I would have had to cut something out of my already very streamlined program.
Having discussed the matter with a person of very good IB skills and having "tested" mine from my previous methods ( Full contact work and Iron wire), He said that it would not be a much benefit to me to devote that much time ( he did suggest a "short version" that would put the finishing touches on what I already have).
In short, we need to realize that the only way to make a correct conclusion is to DO it or at least see it done/test those that have it.
Then it falls on us to decide if it is "worth" the time to be invested.
Psalms 144:1
Praise be my Lord my Rock,
He trains my hands for war, my fingers for battle !