CS2.4 count update: Rob responded that there were about 2300 pairs of CS2.4s made, of which "only a few at the beginning were with Lex XO boards, before buying completed XOs from FST." That count makes more sense.
However it doesn't answer the quality decline riddle. I have (veiled) insider information that after Jim's death in 2009, and possibly earlier, Kathy cut costs in all the products. It is likely that she authorized the change from propylene to mylar caps and lesser coils. Just speculating on who and when, but we do know the what - some later versions were lower quality than earlier ones.
What I would love to know is whether Wes Philips 1991-1992 pair has Thiel or FST XOs and at what quality level. Reviews don't get much better than that one, and Wes was about as good as reviewers get. I'll see if I can tease an answer to that riddle out of Rob. More later.
