I suppose this is not too different than the questions regarding having your projector or flat-panel "professionally calibrated" vs relying on "factory setting" or just "tweaking" the settings yourself. OT1H it is pretty well accepted that the "showroom settings" default to a "melt your eyeballs" mix of hyper-brightness and super-saturated colors. Too many "calibration professionals" are intent on using settings that may look awesome in a pitch-black theater but are not exactly what you want in any kind of "normal" TV viewing. Fact is even the best sets are not going to do their best when there's sunshine streaming in from the horizon and honest calibrators will gently suggest that maybe some window blinds are a better investment than paying them hundreds to painstakinglu balance minute color / contrast / brightness settings...

Similarly the details of what all the speaker / audio electronics firms say relies on having a listening space that is has had at least some thought given over to control of sonic anomalies -- those big atrium style rooms in modern homes are going to introduce very different kinds of distortion than a foam-covered demo space.

Just as some folks prefer colors that "pop" a bit more than real-life there is nothing insanely "wrong" with have some subtle audio tweaks to make the upper mids a bit "enhanced" but the ol' caveat of logarithmic power increases for modest db boost is the real killer -- http://www.ecoustics.com/articles/secrets-amplifier-speaker-power-requirements/

With a smart understanding of how to gently set the width of the PEQ you can make a subtle or sharp change to the sound -- http://www.therecordingsolution.com/use-parametric-eq-settings-like-boss/