It's not that simple. There's other factors at play. The primary one being dampness. A damper board will feel more stable. Stiffness doesn't necessarily equal dampness. Dampness really just comes down to personal preference. Some people like a really damp board while other people think that really damp boards just feel dead and lifeless.
"People say that marijuana smoking is going to get in the way of my career. I say to them that on the contrary, my fighting career is getting in the way of my marijuana smoking." -Nick Diaz