I have seen it here time and time again, people saying they are going to wait for the next generation of iMac as the current version will not let you use the 5K screen at an external display. I am curious as to why you would want to do that? Would you not think that by the time the next itteration of 5K iMac comes around that they cost of a stand along 5K screen will have dropped well below the cost of what the next 5K iMac costs?? The only reason I can think of for wanting to use the display externally is that when the iMac becomes functionally obsolete in there are much faster processors out there and this Mac is just too slow to be useful, then you can save the screen to use as a second display. But on the flip side to that. I would not say that moors law has held up in the top end i7-2600K cpu that I bought over 4 years ago is 15-20% slower than my new i7-4790K chip inside my new 5K iMac. If CPU speed follows the same trajectory, in 5 years when they consider this iMac obsolete, the speed of the newest CPU won't be much better than what I have now. So as long as this computer still works, it will be just as functional. What will likely change is we will be using 8k or who knows what sort screen that will make the point of wanting to slave this screen as moot. Am I missing something here?