Actually, it WAS brought forth by Marc (FilmMixer), although potentially easily missed. At one point, I asked him specifically how his calibrated HT system sounded in comparison to the mixing stages where he worked, especially how his own soundtracks compared in his calibrated HT vs the calibrated mixing room. His reply was that it translated very well, but his calibrated HT sounded a little louder than the studio, and as such he found that -5db sounded on the calibrated HT sounded closest to the studio. Since he also uses an RLO of 5db, that effectively means that -5db with NO DEQ sounds the most accurate to him on the HT setup. That's what I've been using most often for Reference viewing since (although I do crank it up to '0' for some tracks that I particularly like ).
I actually remember the exchange now you jog my memory. I listen at about -5 or -6dB usually too - but I have DEQ set without a RLO. I will try it later with RLO of 5 and see how I get in with it. I am pleased that I can subjectively hit in my HT what Marc was hearing in his mixing room though!
IIRC at the time I was using a RLO of 5 too. I used that for a long time - but since I put in all the acoustic treatments, I have drifted back to no RLO. No particular reason that I can recall why that would have happened.