That’s really interesting insight, Tom.
As to possibly different design decisions made by that newer 2.7 team, I’ve posted earlier in this thread, Philip Bamberg who worked on the 2.7 design had posted in another forum:
Philip Bamberg: I can vouch for both the CS3.7 and 2.7 speakers having a 2dB/decade downsloping response from 200 to 2kHz, transitioning back to level in the treble. This is a tonal balance curve similar to many high-end speaker brands. However such a speaker still does not sound dark (there are other more technically involved reasons for this).
My 2.7s indeed don’t sound "dark" (though a tad darker than the 3.7s) but they certainly are sweet and easy on the ears. I wonder if that downsloping response was something engineers like Bamberg brought to the table, vs what Jim would have done?