Well my air 1 has the same resolution display as the air 2 and it is certainly not pixelated. The screen on my 6+ is better but the air has a nice screen too.
I wish my eyesight was half as sharp as yours. I literally can't tell difference between my Air and my 6 plus. I grew up watching 480i television screens, so to me these new displays are far from pixelated. That retina iMac must be amazing, though.
The 5K looks insane. Ever since I got mine both the 6 Plus and Air 2 don't look nearly as impressive. The 5K is so bright and detailed it makes everything look bad in comparison.
I am loving the Air 2 though. My iPhone 6 Plus feels fat now and I'm already wishing it was as thin as the Air 2.