I have gone thru a couple of 21.5's on this gray bar test. So, yesterday, we bought my son a cheap 26" Dynex LCD tv at Bestbuy for him to use partially as a monitor. When he was out of the bedroom, I ran the gray bar test. Wow, you think your imac's have issues? Haha. Funny thing was the yellow was at the top of his display. As the good dad I am , I did not show it to him. It looks freaking great running WoW and he's happy. Why ruin that for him by showing him that test? So, the moral to this story... if you have a friend that is happy with their imac, do not, I repeat do not, show them this test.