Hello there everybody, I have a 2013 13" MBA for sometime now, which is a great device. Recently I got interested in upgrading my stationary work desk, to use it with my MBA when I come home. I got interested in the Dell P2415Q (4k screen - 680$), but after looking up the compatibility on the net, I found some reports that say even a MBA 2011 (!) got to show in an external monitor at 4k, and some reports that say a if you want to produce 4k resolution to an external monitor, you need to have the 2015's new MBA, at least (some reports claim it's connected to the thunderbolt 2, too). Well after this phase, I started looking at the Dell U2515H (2560x1440 screen - 640$), which I know my macbook can produce it's resolution. And now the deal breaker - after looking at local used products listings, I found a guy who sells his iMac 2013, 21.5" 2.7GHz, 8GB RAM, 1TB 5400rpm - 1130$. Well, at first I said I don't need another computer, but after rethinking, maybe that's what I am looking for. For me it's spending more than I expected, but what I get is: Another mac, which is comfortable to work with at home, (21.5) Apple's screen quality and colors, and the option to plug my MBA and switch the screen to display it's contents (Command + F2). So guys, what do you think? I'm in some kind of a dilemma, on the one hand, I can get higher resolution Dell screens for a lower price (which I still need to check how practical they are - 4k with MBA 2013), and on the second hand, I can get the built quality, screen quality of an apple product, which is a computer and a screen too, but it's resolution will be "only" 1920x1080. Of course, I have to mention, there is the 2560x1440 Dell option, which I do wonder if I should get, and close the deal, how is it compared to the iMac? The prices written are according to my country. Thank you very much, and waiting for your answer, orl2008.