Received my pair earlier today so I'll give some short impressions.
They are very fun sounding headphones. Not as detailed or transparent as my HD800 (go figure), or my LCD-3, but I do prefer the bass impact and presence on the TH-X00 over both. It doesnt have
more bass, but it seems more pronounced. To me, that's worth the
small hit on the resolution. Now I sort of want to try out a pair of TH-900 to compare.
Earcups work fine for me, though I have to angle it a specific way to get my ears completely surrounded. Not a big deal.
They are pretty comfortable, but not as much as HD800 or T1s in my opinion. That could change with use over time.
I don't know if I would have bought it at 2x the price, but I would not have been surprised they were. I think $400 is a great price, but unfortunately haven't heard too many in that price range to compare. Its good enough that I wouldn't prefer my hd800/lcd3 100% of the time. A good complement.