Now waiting for my 3rd iMac to be delivered, first had yellow patch and weird backlight issue (faint dim lines), second ones yellowing is so bad it makes greys look almost brown, and it's gouging the hell out of my discs, and where the bottom of the glass meets the aluminium, the glass is sticking out like it wasn't inserted properly. Iv had 2 iPhones too as first had dead pixels and second (one I'm using now) has the glass sunken in on the right side, sharp enough to pull a bit of my nail off, I think apples quality control is non existent