All of this technical talk about the design of the LCD-3 is interesting, but way above my head. I'll just offer some layman's thoughts.
I've now owned my LCD-3 for over 2 months--I ordered on the first day of the pre-order. The reports of production variations and veiled/recessed midranges are definitely alarming, but I can't say whether my unit suffers from these problems. I brought my unit to a meet in Virginia yesterday, and if anything, people seemed to think the midrange was one of its strengths (though we didn't have any other 3s to compare with).
I've definitely grown to enjoy my 3s more with time. This is partly because, after a few weeks of bending the headband and stretching it over the arm of my couch, the clamping force is tolerable for at least 1-2 hours at a time. It's still far from what I would call comfortable, and trying out the SR-007s yesterday reminded me just how lightweight headphones can be (and still sound amazing).
For whatever reason, I'm appreciating the LCD-3's sound more too. There are some times when I'm not very impressed by or immersed in my listening session, but there are lots of variables--my mood, the quality of the recording, ambient noise, etc. Overall though, the sound I'm getting feels very honest, realistic, and detailed enough that I don't see any immediate need to upgrade my source or amp.
Now I'm on an obsessive quest to find the best-recorded music I can. My recent favorites: the Living Stereo box set sounds consistently amazing, and the K2HD re-master of the Getz/Gilberto album is just stunning. I had probably heard that album hundreds of times before, but hearing that re-master on the LCD-3s is like hearing it for the first time. Getz's sax has never sounded so pure, immediate and real.