I just wondering if a 4k 28" will be almost as good as the new 5k imac when it comes to working with Text. I know that a MBPr 13" at 1400x900 or 1680x1050 looks almost as sharp as the "retina" resolution at 1280x800. So, when you use a 4k 28" display and use the "scaled" 2560x1440 resolution it might look also way more sharp than on an "old" 27" imac with 2560x1440. Does someone have experience with this? In other words, when a lot of us will not be able to use a 5k display due to the lack of thunderbold 1.3 in the future, maybe it's not a problem and a 4k will almost as good?