I've replaced the plastic pins on several of my Martin dreadnoughts with bone, and been very pleased with the results. But on one guitar, my D-41, the difference was minimal.
My D-45 was used when I bought it. It came to me with D'Andrea Brass Pins, and I couldn't get those off fast enough; they just killed the resonance and the tone. Going back to plastic was huge, and then going to bone was very dramatic as well.
My Taylor 710CE came from the factory with ebony pins. I switched those out for Tusq pins...again dramatic. More volume, dynamics and resonance, for sure. I'm also using Tusq pins in a 2004 straight-braced D-18 with similar results.
I think pins make a difference, but it sometimes depends on the guitar.
Bill