well, i have seen a pattern in my own process:
1. mixes = typical RMS of -22 to -18, peaks at about -6db. that's a pretty large crest factor.
2. Masters = Typical RMS of -10 (sometimes 9), peaks limited to -.2db.
and even though i thought my masters with -10 RMS average were pretty good, and strong without sounding super squished, and not fatiguing......
they still come out to about DR 8 or 9.
which i'm not happy with, so i'm gonna start backing it off.
it's 'The Way' you get to just below 0db, that matters.
and everybody does it a bit differently, and a lot of the ways i hear it, i don't like.