Probably a toss-up. If you choose to use a very high-end external DAC, you also encumber the jitter imposed by the digital interface.
I am using a BDP-95 with an Eastern Electric DAC Plus.
When streaming FLAC files through the Oppo with Asset DLNA, the EE DAC renders a much cleaner presentation with significantly better bass than the balanced outputs of the 95.
I was somewhat surprised by the result given both units share the same Sabre DAC chip.
I am using the Oppo 93 with a W4S Dac2, streaming files wirelessly from a Netgear ReadyNas. Using an Atlas Mavros 75ohm digital cable (1.5m). The only difference between the 93 and 95 in terms of transport use (not analog), is the power supply being linear in the oppo 95. Overall the combination gives me very rewarding sound, airy, silky smooth with great soundstage depth and inner microdetails. Wasn't planing on using the Oppo for such use but it does do very very well as a media transport in stock form.