Finally I've been able to detect a chink in the LCD-Xs armor, one that has been alluded to before (by someone whose name/avatar I don't remember) in this thread: these headphones are not made to be played at lower-than-average (or even average, for that matter) levels. You have to listen at higher-than-Average (the higher the volume, the happier they are) in order to get the full potential out of them. The problem is that these headphones are so non-fatiguing because of the darker/"mahogany" sound that you may end up damaging your hearing without even realizing it. By the way, it's not a matter of power...the RS Darkstar and EF-6 are extremely powerful (at least for these headphones) and still, this issue remains. If someone doesn't like the sound of the LCD-X, it is because they listen to music at Average or lower-than-Average levels. At lower levels they can sound uninspiring and grayish. For lower volume levels something like the T1, HD600, PS1000, and others would, in my opinion, be better...other than that, pure perfection.
I tested this theory today with several types of music. My conclusion is yes the X sound better at higher volumes but the sound quality does not totally degrade to gray at lower volumes. The mids/voice and bass drop out first. The biggest effect was with classical music on quieter passages where the whole orchestra is playing. Then, the X lose definition like probably any headphone would. I actually liked the sound at the lower volume levels.
With other types of music - rock, country, acoustic - the effect is less noticeable. On most music, I still heard good definition even at sound levels below where most everyone will listen. I also didn't hear much difference on piano pieces including classical and jazz.
And thanks, Figaro. I got to listen to some classical music today. Still waiting a proper DAC/amp combo...