While surfing the internets, I found this list of drummer jokes that someone has maliciously edited into bass player jokes. These are the worst ones. This is not funny at all. This is the sort of thing that gives guitarists a bad name.
Q: How many bass players does it take to change a light bulb? A: Only one - but the guitarist has to show him first.
This really puts a dent in the whole tonewood argument.
I doubt there is anything very special about those piezos. My experience is that you need the right mounting and electronics to make a piezo sound good, and it has very little to do with the sensor itself, which is just a little bit of semiconductor.