I just received my (late 2012) iMac 27. I have it side by side with my late 2009 iMac 27 and the new unit is not as bright as my 4 year old iMac. I have checked brightness levels, maxed both, turned off automatic adjustment and also determined both units are using the same colour profiles. Has anybody had this experience? It seems to me my brand new iMac should have a display that is at least as bright as my 4 year old one.