Re: Vandoren mouthpieces
OK, so I was so intrigued by the duplicate specs that I contacted Van Doren myself. Here is the very interesting response that they sent.
"You are correct, the tip opening and facing length of the A25 and the A20 are identical. The only difference is in the thickness of the rails. The A20 has slightly thicker rails which does add a bit of resistance to the mouthpiece. This can result in a mouthpiece that may be a little darker, has more resistance of attack, and can also work better with lighter reeds."
An interesting explanation, but why don't they give some hint of this in the spec sheet?