My old 1964 Gibson J-45 came to me with plastic pins. With the bridge being the old rosewood adjustable, it eats up much of the vibrations, therefore making a more "mellow" sound. Recently when I had fretwork done, some of the old pins cracked & broke off in the holes. At the request of a friend who is a guitar repairman, I tried brass, and bone & ebony pins. We did not notice enough of a difference to make me come up off the big bucks. I replaced the original pins with plastic ones from Gibson. You just have to try them & you make the decision based on what sounds good to you.