As explained to me by Leonard(ARC customer service), the CD7
receives only the PS supply upgrade, not the new DAC. I have
a CD7 and feel that it has the best midrange of any digital
piece I've heard. I preferred it to the Krell 505, AMR,
Marantz 7SA1, CD12, and others. My old Krell 20i is still an
option, and on the same level as the CD7. In most cases, the
sound is just "different" and the choice is based upon your
preferences and synergy with your equipment. I recently tried
a terrific new player from Playback Designs and found it
basically the equal of the CD7 and 20i...again, different
although very similar to the 20i. Of course, anyone interested in SACD might make different choices.