I need to purchase a new Mac computer to start developing iOS apps using Xcode/Swift. It's my first time Mac. I know its kinda of portability choice between the 2 models but It's not an issue with me as I'm not travelling a lot nor develop apps outside home. So my main concern is that to be comfortable with coding. (screen size factor, Retina display, ...etc). Inline with this, I know that WWDC will be held after 20 days and I'm not sure shall I wait until then may be they would announce for any new 21.5 iMac? Any advice would be much appreciated!