This whole thread feels like one of those "I can tell the difference between an MP3 encoded at 320 kbit/s and one encoded at 256 kbit/s!" audiophile threads. Yes, there are probably people out there with well-calibrated ears who can, but I am sure not one of them. FWIW I have a 27" 5k iMac and can't even remotely see any difference between the images.