I have a 27 inch i7 680 mx 1 gb fusion iMac. I have returned a few of them for scratches etc. the only thing I can tell is wrong with it is the fans are a little Loud. I am reading all these threads about image retention and am getting worried. I don't seem to see any IR but I haven't used the computer a great deal. What happens after the initial 14 day, I do have apple care. Will I get a new computer? If they fix it and scratch it in the process will they fix that. I am almost so worried I am thinking of returning for something I don't have yet.... Are all of these 27 have IR?