Got mine yesterday and put it on my ergotron arm. Haven't seen any dead pixels yet, but will do some more looking. From what I can tell BLB seems to be minimal, and a little less than my PG278Q.\
The picture below is in a completely black room, with an ISO of 3200 as that was the only way I could get any light on the monitor to show up on the camera. I have a picture of one with ISO of 200 and 800 and I couldn't see the monitor on the picture. I used Eizo pixel checker black screen to test. Luminance was around 25-27. Anything higher than that, and it was painfully bright in games.
ISO 3200 really extenuates any light areas on the monitor, and in a completely black room, it was pretty even. Is this on the better or worse end of these monitors? Might order another from Amazon to compare. I don't really use in complete dark, but will test with more games and more time.