Lew,
I recently auditioned a Diablo 300 non-DAC being fed by a DCS Bartok. The Diablo is a great integrated; as crazy as this sounds, the Bartok ruined the presentation; too clinical of a source. Diablo's bass is incredible! The mids and highs were slightly bright to me, thanks to the Bartok. Over the years, I have auditioned various Mac products, but none ever wowed me. The C2700 and MC611's are a great combo, but I do not think better than $10K. The DAC in the Diablo is dated; there are much better DACs out there. Go the Gryphon route and purchase a Lumin X1 used; you can stream directly to the Gryphon and have a little fun by utilizing the X1 DAC. If this was your system, I am confident it would outperform the Mac system on all parameters.