That's my conclusion as well, our Mikuni is trouble free now we have ULSD.
Eberspacher seem to be ok in road vehicles but not in boats and really the only difference seems to be fuel quality particularly the absence of sulphur in DERV.
Mikuni advertise as being suitable for red diesel but my experience is different, they say red diesel, not gas oil, which is what boaters have had to use in the past. Besides I can't see how a Mikuni can run on red when Eberspacher can't, after all the combustion process works on the same principle.