I have a top spec, late 2013 rMBP, and got an email today from youtube about 4K video so I thought I would check it out. But really, it is all a little underwhelming. Here I am expecting it to look like pixel perfect moving photos and it really doesn't. Not even close. For instance, the sky on this video ... https://www.youtube.com/watch?v=AIfWzm6O9gg&list=PLbpi6ZahtOH6qU1WZzpcYz6hPhPRMByo8 ... I can see lines of block colour. image ru It just seems a little rubbish to me! Is my computer no good, or is 4K just a gimmick?