(Incidentally, I always do the same thing with the amplitude in the Hi-Res Stereo and Surround Sound files as well. Some SACDs are mastered at a ridiculously low/soft level, for some reason.)
i remember when nine inch nails released their last album, they have two versions, one standard mastered, and an "Audiophile Mastered Version" (
http://www.realhd-audio.com/?p=1521).
"Audiophile Mastered Version" has extended dynamic range, not meant to be competitive in the loudness war.