My Series III is an early model, not a Jubilee, so I had to have my tech re-spring this neck. It fits perfect in the tenon though and has all the same measurements as the standard neck. The silver neck has changed my sound, in that it is brighter, louder, and easier to make it into altissimo. I don't know why, I don't care either. I like it a lot. Is it worth the extra cost? Maybe, but probably not for everyone. I wish people had an easier way to try before they buy.