"This amp goes to 11..."

Seriously, there are so many variables/factors in this (including user calibration) that you really can't compare one system to the next.

I have very efficient speakers (Klipsch Cornwall mains, Klipsh Heresy side/center), and around 6000W of amplifier (big rack of Crown PSA-2's, most of them bridged).

I have configured the system (amp gains, cal settings) so that "loud" is in the -20db range. Goal, in part, was to maximize signal to noise ratios. If I ever decide that I want the system to be able to go louder, it will be easy to achieve :-).

I wouldn't worry about it-