The LCD3s are nice headphones. Fun with pop music and some electronica. Nowhere worth $2000 with all the flaws in the sound reproduction. I think someone who hasn't heard electrostats and wants a different signature than the HD800 could live happily with them, but when you've heard headphones that are superior in the majority of categories (just from a listening, not measurement perspective), the flaws are distracting and you're continually reminded by everything missing and reproduced incorrectly by the LCD3.
I could only find one genre where I could stop critically listening and just enjoy music on the LCD3. I don't like having gear for just a single specific genre of music.
The TP actually does help. I noticed slightly less detail with the TP, but it helped with the bass, as well (though not as much) with the mids and highs. If I owned the LCD3, I'd probably keep some sort of dampening material in.
I liked the LCD3 more than the LCD2 R2, but there are still too many inherent characteristics to the headphones which would keep me away from them, even if the price was halved. People who like the LCD2 will probably appreciate the LCD3. They're definitely more comfortable than the LCD2s.