Not running that exact rig but...
I ran my newly acquired R-09HR the other night and went with the suggested 50 setting. I ran AKG 460 > w-mod+ UA-5 > R-09HR (line in) and my L/R levels on the UA-5 seemed to be in about the same spot (1/2 - 2/3 volume) as before running into DAT, I think it turned out really nice sounding. This will be the main question when I call the marketing director at Roland back to give feedback and will report to the board here what he says about unity.