Well, I received my LCD-2 rev 2's yesterday. After the first 20 minutes of listening, I knew I preferred them to the originals. I ran them overnight, and they are still running now. The sound seems to have improved slightly since yesterday; bass is solid, deep, and detailed; with some tracks, not much of a difference in the low end from the rev 1s, but with others, especially music with acoustic string bass, there is quite an improvement in the bass quality.
Midrange on the rev 2 is, to my taste, superior to the rev 1; vocals are not quite so forward, but seem properly placed in the mix on good recordings. I like being in the front row, but not on the stage. The rev 1 midrange always seemed a little thick and closed to me. I like the new mids better.
Highs just seem to be a bit more open and airy, if those are the proper terms; cymbals just sound correct to me now.
I'm using these with a Mac Mini / iTunes AIFF files / Stage DAC / Concerto setup, and I'm very pleased so far. Overall, I think the improvement for me is worth the purchase. And if a couple of hundred hours of play time on these will improve things further, I can't wait. I'm a Dire Straits and Mark Knopfler fan, so I'll be working my way through the group's 6 albums, followed by Mark's 6 solo albums, which I think are all excellent showcases for the LCD-2s.
By the way, my rev 1s are up for sale in the Headphones For Sale forum (along with a few other pair, I know). I'm including both the original foam/metal headband, and a new leather one with them. You can check out the listing
here.