Maybe three days I don't check this thread, and suddenly the page count explodes! At least I found out about Rev.2. And hamsters (is Kia sponsoring this thread?)
My original phones failed 5-31-11, after exactly two months ownership, and thus were Gen.1 (or Rev.1 if you prefer.) Got the new ones a full three weeks later. My initial, right off the bat, impression was of a brighter, more illuminated and slightly more detailed top end. In other words, a bit more like electrostatics but with true clout at the low freqs. All neatly explained by the new drivers being rev.2s, since confirmed by email from the mothership.
My pair is only two serial #s off from another Head-fier who has posted graphs, and was tested 6-16-11. If Audeze had handled my return more efficiently, I might have gotten the previous drivers. Silver lining, I guess.
Bottom line, I am happy to have the rev.2, and find the treble pleasing rather than threatening. Perhaps the Golden Lion (new Russian prod.) tubes in the Lyr help, though even with solid state I never found the LCD-2s to be over-trebled.
In reference to questions asked earlier on the thread - the first album I play through any new gear is Hounds of Love by Kate Bush (1997 EMI UK remaster.)
And my first encounter with the LCD-2s was a picture and review tease in The Absolute Sound in Feb. "I gotta have those," was my involuntary thought. Does that make me shallow? Or was it a case of You CAN Judge a Book by Its Cover. (Stop me, before I cliche again.)
As to burn-in, as opposed to your brain/ears becoming accustomed to a component, in my experience it's real but not a constant. My Triangle speakers sounded like X-ray machines when first played, and took probably 300 hours to smooth out and settle in. With most electronics, changes are too subtle for me to notice. YMMV, and if the factory does it, like Audeze, it will most likely be a non-issue. My new LCD-2 pair hasn't changed that I've noticed after more than 40 hours. Time to go do more research, methinks...