There is an interesting letter from a reader in the latest Electronic Design (http://www.elecdesign.com/Articles/ArticleID/15199/15199.html, bottom of the page) in which a reader points out that he doesn't believe that there is significant difference in the audio characteristics among various film dielectrics. He also says that he has stopped trying to convince so-called "gurus" of this.

The editor, Bob Pease, concurs and bemoans the difficulty of convincing these people of the value of ABX testing.