Spoke to Kal yesterday about another issue and the new Ref CD-9 came up. As far as the "red book" CD side of the house, Kal said the CD-9 is better (no surprise) than the CD-8, principally because the CD-9 uses upsampling which greatly improves the sound and bandwidth. I think, but am not sure, that Kal said the DAC is the same, but as stated, the upsampling feature is the main improvement.
OTOH, the "other side of the house" . . . well that's all new and designed to provide flexibility for all sorts of new formats and inputs. Frankly, I didn't understand a word he said because I am resisting going down that "DAC" (pun) road. If anyone gets a chance to hear the new CD-9, please report back.