Do you mean the 3.6 made it, but the 3.5 and 3.7 didn't? I strongly disagree with that. Every model in the 3 series was an innovative step forward in audiophile speaker history. The O3a was reviewed as unmatched in palpability of imaging. The CS3.5 was an O3a and 3.0 perfected, with an EQ that really brought full bass to a reasonbly priced speaker along with every audiophile quality fully provided.
The 3.6 sold a lot, and was a little better than the 3.5, but not so revolutionary in the history of audio. The 3.7 was the designer's testiment in revolution, execu5ion, performance, and accuracy including the most advanced custom driver designs ever yet marketed.