Picked up a 46EX500 today (so this has BE3 rather than BE2).
Early thoughts: I watched the "caves" episode of Planet Earth. Was able to achieve deep blacks, but lost too much shadow detail. The point of happy compromise yields both more than satisfactory blacks and shadow detail. I haven't yet watched a dark movie in a dark environment, however.
Matte screen is excellent. My screen is orthogonal to a large window opening onto my balcony. There's some glare, but it's quite muted. No concerns about the picture lacking vibrance (but I don't like the oversaturated look of the Samsung glossy screens).
Haven't noticed any uniformity problems.
Have used it as a PC monitor for my early 2008 Macbook Pro. I read a lot of PDFs for my research, and these come up crisp and clear. So this doubles as a great monitor when I'm working at home. I've also played a few games and the motion and picture is excellent.
On lag: I was a little worried about this lag having seen that YouTube video. But having played with the TV for a little, I'm pretty confident that the video shouldn't be trusted - although I don't really have any solid data to back that up. The lag on that video is comparable to what I'm getting *with* motionflow, etc. turned on. Once I turn off those features, the lag is noticeably and substantially better. Which is not to say that the lag is acceptable. It's certainly still noticeable if you look at those input lag timers. But in my brief real world testing, I haven't found it a problem - but then I've only so far played Oblivion, which is hardly a hectic game. I'd be happy to do some tests, but I don't have a fast camera. If there's another way to get reliable results, let me know and I'll see what I can do.
Overall, very happy.