Home theater mixes are mixed 3dB higher than theater mixes. It would be useful to have a preset to lower Ls and Rs idividually by 3dB to make the mix (more) conformant to theater mixing.

Also, is this adjustment done when using the upmixers in DoM?

References:

Tomlinson Holman, Surround Sound : Up and running (2008), pp. 162-163:

"Level Adjustment of Film Mixes
The calibration methods of motion picture theaters and home theaters are different. In the motion picture theater each of the two surround monitor levels is set 3 dB lower than the front channels, so that their sum adds up to one screen channel. In the home, all 5 channels are set to equal level. This means that a mix intended for theatrical release must be adjusted downwards by 3 dB in each of the surround channels in the transfer to home media. The Dolby Digital encoder software provides for this required level shift by checking the appropriate box."

Steve Guttag ( http://www.film-tech.com/cgi-bin/ubb/f16/t003494/p2.html ):

"[T]he surround levels in consumer are not the same as cinema...we, unfortunately, have clung to our legacy of mono surrounds going back to the 1950s so each side is at 82dBc for 5.1, each surround channel is 82dBc for 7.1. Consumers wisely realized that mono surround has no place in the digital world so each channel is the same (surround or stage) so if you set your surrounds to 82dBc, you'll need a 3dB boost to get them up to consumer levels."