Here is a tale of woe. I'm not crying foul, or expecting sympathy or anything of that sort. I just wanted to express on a forum how disappointed I am with Apple's quality control on their 2012 27" iMac. So here's how it started. Ordered a 27" i7 iMac on Apple.com the second they went live back in November, 2012. Received iMac December 15. All was fine. The screen was a tad yellower than I would have liked, but I was willing to live with it because I had no screen bleed or other screen issues. I had the typical IPS "glow" in the corners, but no bleed. However, I started to experience a terrible buzzing from the graphics card whenever I would be playing games that taxed the GPU. It drove me nuts to the point of setting up an exchange. However, that took about six weeks to organize. The first replacement had a nasty piece of "dirt" of some sort under the glass, right in the middle. The second replacement, third replacement, fourth replacement had absolutely ghastly screen bleed, and I've been forced to basically stick with my the fifth replacement, which - while not perfect (I don't expect perfection anyway), is "acceptable." I took some pictures of three of the replacements. I know this is not scientific, but the bleed on these LG panels was beyond acceptable, especially when watching a movie. My wife even peered in a few times and had several exclamations when I asked her for her opinion on whether these panels were acceptable. All these pictures were taken at 65% iMac brightness, which is "normal" brightness level. Also note that the "bleed" in the top left and right of each iMac is NOT bleed, but simply the IPS glow. All iMacs will glow like this in the top left/right of the display. If you move your head directly in front of the glowing top left/right corners, the glow will disappear. Anyway, here was one of the replacement systems. Note the outrageous screen bleed in the lower left region. Watching movies on this was, in a word, awful. Just awful. The next iMac wasn't any better, but just smeared that bleed around the left side of the screen. There was literally NO black levels on the left side of the screen, and this was by far some of the worst bleed I've seen on a consumer electronics display: And then the last iMac I took pictures of, you can see how there's reasonably better black levels on the lower left, and then the lower right is this insane hotspot of bleed. Crazy... So there's my tale of woe. To Apple's credit, they were able to see the issues themselves in their back room under "normal" lighting at the store, and apologized profusely for the issues. It is is possible to get a mostly yellow-free/bleed-free iMac, but it may take quite a few exchanges. Oh, and none of the replacement iMacs experienced the terrible buzzing noise of my first one, so that's something at least. It's just a shame, the whole thing. The 2012 27" iMac is simply fantastically powerful. That Apple managed to stuff an Intel 3770 CPU, a 680MX 2GB GPU, PSU, RAM, several drives etc, and have it cooled by just one extremely quiet fan (in normal use) is a testament to fantastic design. It's a shame the LCD panel is by far (to me at least) the weakest link in the whole setup. I can't speak for other people, but I'd be happy paying several hundred dollars more to guarantee a higher quality panel. I really hope nobody else has to go through the nightmare of iMac exchanges. Thankfully my boot OS is on a Thunderbolt SSD, so I didn't have to spend hours reinstalling my OS. Just connect my drive and away I went! Still, lugging an iMac back to the store over and over was not my idea of fun. Thanks for reading.