I queried Schiit as to whether I would be able to detect a significant difference between the Bifrost and the Yggdrasil, and their surprising answer was "no."
This answer maybe different based on who you spoke with at Schitt. I called them a few months ago to discuss the Yiggi+ MIB DAC. The guy I spoke to cursed out the Yggi+ LIM DAC that I owned and told me the Yggi+ OG was much better. I took his advice and got the last OG available (Schitt replaced it with the MIB).
It took a month of burn-in for me, the same as what Robert Harley reported in TAS a few years ago. However, after that burn-in I could tell that the OG was much different than the LIM. Either could be preferred by people over the other. I love both and have then in 2 separate systems.
I have not heard the Bitfrost but based on my experience I described above I would think the MIB or LIM is much better than the Bitfrost. It would of course depend on the sonic match with your system and how revealing your system was.
I use a used $700 Sonore OpticalRendu streamer, which uses fibre optic cable (glass) just before it goes into a USB conversion and into the DAC. Not as pure a fibre solution as the Lumin X1 (owned it before) but close in execution.
Only issue with the Yggi+ DACs is that it sometimes shuts down for 1/2 second between songs on a ROON stream. That is if the next song is a bit slow to play. Irritating at first but the sound of the Yggi+ is so good that I do not care. Saved me $20k by eliminating my desire to buy the Playback Designs DAC.