They have identical DAC's (PCM67) so I think the CD will sound better due to the fact that the digital signal will reach the DAC with less conversions (avoiding the potential jitter-inducing SPDIF connection).
BTW, PCM67 is one of the first chips from BB (now TI) to use a mixed R-2R (multibit, 10 bit) with delta-sigma (1 bit).
Performance wise... they are not so great, the R-2R part wasn't very good (THD+N only -86dB).