Hi guys, would like to get some advices from all of you! Currently, I got 2015 15" rMBP for my work. I usually do iOS coding, run simulators, some light Photoshop work, and of course some web browsing + email. I realized that the screen is actually too small for me, would like to have some kind of upgrade. Initially, I was going to buy the new iMac for Target Display Mode, so I can use the new iMac as external monitor and my second computer. However, I have tried it with my 2015 rMBP via TB2 adapter, and no luck. I usually spend time working on code at home and Starbucks, so I will still use the rMBP even I got the iMac. Then, everything went into this dilemma.... Should I still spend $1800 for the 27" new iMac / spend $600 for a nice 4k external monitor? I feel like even I spend $600+ on the monitor, I still wont get the good quality as iMac which makes me very frustrated.... Any inputs are greatly appreciated !