I use my Esoteric X-05 as transport to my external dac except when playing sacd. When playing sacd the Esoteric uses its own dac. Esoteric has both single end and balanced outputs so its easy to switch source. Used a Krell KPS 30i as transport before Esoteric but the advantages of beeing able to play sacds without another "box" in the main setup won. The Krell serves as transport in my second setup now and does it very well (recapped and serviced 1 and 1/2 year ago).
Conclusion: I can recommend both Esoteric and Krell as transports. Neither of them will play sacds when used "only" as transports.