After talking to a friend who's installed one, and reading comments from others on this board, I ordered a Wittner tailpiece and nylon "tailgut" from Bob G and installed it on my Czech bass last night. It's hard to sell without being able to A/B, of course, but the bass does sound louder and more resonant. The old tailpiece looked like ebony, but it turns out to be a very light colored wood stained dark. It's not very hard, either. I wonder if perhaps the improvement I hear in the wittner isn't due to the light weight, as some have said, but perhaps to it being made of a stiffer material? I suspect a soft tailpiece would absorb a lot of the energy you're putting into the string and turn it into heat, and not sound. Or perhaps it's a combination of the light weight and stiffness. Perhaps the lutheirs in the community can comment.