The 9000ES' DAC is probably equal to a $300 external DAC. I would not expect it to match a $3,000 Levinson DAC.
Several months ago, my 22 year old and I listened to several CDs to determine if we preferred the digital or analog outs. We prefer the analog outs, but it was close.
But I'm not a good test. I have a $2,000 Rotel 985 pre/pro. The analog outs feed into the 5.1 input and the signal stays analog.
With the digital input, the signal is converted to 24/48 in my Rotel, processed, and then converted to analog. There may be too many conversions which could be deleterious to the sound.