My dad got a Grade B, and I started inspecting it as soon as i got it out of the box. It took a moment or two, but I found some encasing dingage. He still hasn't plugged it in and tried it out, but I was so enamored with its enormity, no.. it majesty, that I ordered myself a B.
I scrutinized mine, and didn't really find case a problem, and once i fired it up (1600x1200 @ 75Hz) I felt movement in my nether-regions. I almost polluted my Underoos. Anyway, I further scrutinized the display, and was able to detect a hint of login prompt burn-in. Then after a couple days of use, and several sessions of scouring the screen for defects, I came up with nothing. Until, I fell upon a spot during normal use. I would describe it as looking like a "dead pixel" on an LCD, but a VERY small pixel. I moved the screen up, down, left right with the settings, but the spot stayed in same place. I decreased resolution to 800x600 and spot stayed same place, size, so it's not a functional bad thing. When I first saw it, i tried to wipe it off, because it looked EXACTLY like a spec next to it that just wiped off, but i've wiped & fingernailed it, and it seems like a ding(tiny) on the back of the screen glass rather than the front.
Unfortunately, I got the impression from this forum that the difference between A & B was ONLY casing, and never to do with video or screen issues, but I've since learned that grade B means possible screen/video issues, albeit MINOR. I mean nigh undetectable minor.. So to make a LONG post short (ha!). If I had it to do over again I'd go for the A rather than B. 99.9999999% of the time that I use the monitor I can't see those issues, and I don't plan on DOing anything about it(like returning etc). I might just swap mine out with my dad's, only because i have psychological issues having those two things on the screen. I lie in bed awake sometimes thinking about them being there, until next time I actually USE the monitor and I feel better again .
Will De Stijl