Arnold,
Was Jeff using his wooden end pin at his recital. When I was at UNT, a little over a month ago, he was using a type of plug-in wooden end pin and I was wondering if you had any opinions as to the benefits of using wood over steel. When I had a lesson with Paul Ellison at Rice last fall, he was using an oak laborie-style end pin (it looked like a fat pool cue) and he said that it was a kind of extension of the physical instrument to the ground -- more so than the more common carbon fiber rod. Here's a picture of Mr. Ellison and his end pin at a masterclass in Austin:
http://www.bassodyssey.org/images/paul_in_class_1.jpg