I took delivery of my new 21.5 base imac on Monday. Fantastic piece of kit and very pleased with it apart from a concern about the screen!! I have read many threads regarding issues with apple screens. Not just the imac but also ipad and iPhone issues. Such as backlight bleed and yellowing etc. I did in fact replace an ipad 3 earlier this year due to severe backlight problems. But my current one is near perfect! I am in no way a perfectionist nor do I suffer from OCD. And realise nothing in life is perfect! But I am just a bit bothered by my imac screen! If for example I have my calender or safari fully blown. (Or any white/light background) The top of the screen is brilliant white but as you move down the screen it seems to graduate into an off white/slightly yellow. This is especially noticeable when scrolling for example. But if I open an app and it takes up only a portion of the screen it isn't really that bad! The backlight seems ok apart from slight bleed on right but not too concerned about it. The weird thing is. If I stand back from the screen say approx 5'. I can't notice it!! A very nice chap at apple guided me through transfering data from my old pc on the phone. And I mentioned this to him and he said his screen was exactly the same. And I don't think he was trying to fob me off. The thing is I could exchange and get a worse one. And was wondering if anyone else has same issue. Love the machine. It far exceeded my expectations. And some advice would be most appreciated!! Btw. There is no point in taking and posting pics as it just wouldn't show. As like I mentioned if I stand back it isn't noticeable. Only when I am sat down in front of it at my desk!