The problem with "reference level" is that it's a moving target. Calibrating your system to reference is no small task. It certainly isn't as simple as playing the band-limited pink noise in the AVR and using your RS meter to normalize the dBSPL to 75dB.
If you aren't properly calibrated, you can't offer an opinion as to whether or not reference is too loud.
Then there's the recent phenomenon of a BluRay disc that's far hotter (overall) than the DVD version. Thor is the example I posted on back when it hit the streets, but since then I've measured more BR discs as being much hotter than the DVD. Thor BR is +10dB hotter than the DVD. That's 10 times and perceived by listeners in at least one study as being twice as loud.
So, how would you judge if reference is too loud if one version of the soundtrack is perceived as twice as loud as another version of the same soundtrack? You couldn't.
There is also the loudness curve to consider. One disc may be perceived as being less loud even though it's 4 times louder, because of the difference in spectral content at the loudest points.
There is also fatigue in the mix. That is, how much reference-level audio is on the soundtrack and at what intervals?
It might be helpful to single out a few titles rather than a blanket "is reference too loud" question, which, for me anyway, would be impossible to answer. Using the Thor example, reference level when listening to the DVD was not a problem at all for me. When I popped in the BR, it knocked me out of my seat.