Don't think there will be a definitive answer to this question.
My personal preference after much experience is for separate DAC and transport. For instance, I currently own an Aesthetix Romulus Eclipse CDP and I prefer the sound from a separate transport (CEC) feeding the Romulus DAC.
Go figure, I have no explanation. In retrospect I would have been better off with the Aesthetix Pandora DAC.
I figured what the hell the transport in the CDP doesn't add that much cost over the DAC price so I went for the CDP. But I'm not using the CDP drive so what did I save?