tomthiel, "...signal-shaping was done within the amplification envelope..." Wow, that seems quite ambitious, especially when considering it probably would all have been done in analog then. In today's digital era development time an effort would probably be dramatically reduced. I remember just before Jim's passing that he thought that Class D was best limited to sub-woofers. Much time has passed, and perhaps Jim might have come to appreciate the current status of Class D more, or, perhaps not.
I agree with you regarding perhaps moving to a higher impedance. Though at the risk of appearing petty, I think moving the minimal impedance to 4 Ohms would be most interesting. The required amplifier budget has scared me off the CS5i's.