Ranked in these QuestionsQuestion Ranking
Pro Super-light and super-thin
The laptop weighs just 2 pounds and is 13.1 mm thin.
Pro OSX is developer-friendly
OSX is based on XNU (Darwin) kernel, it's certified Unix and arguably a lot more developer friendly than Windows. Development for Unix is native on OS X.
There's a large selection of great development tools available for OSX. The operating system itself comes bundled with a powerful terminal emulator, called Terminal. Additionally, Apple provides tools, like Xcode, an IDE that contains a comprehensive collection of tools for developing OSX and iOS software, for free.
Pro Available in 4 colors
The laptop is available in space gray, gold, silver and rose gold (pink) finishes.
Pro Very good speakers
For such a thin laptop, the MacBook offers very robust sound, and can reach volumes around 80 dB.
Pro Good battery life
The battery lasts around 7h30m of continuous web browsing, and manages to last an impressive 2h35m under a total stress test (maxed out brightness and processor usage - circumstances that you are likely never going to encounter in the real world).
Pro Completely silent operation
Thanks to the Core M processor (which doesn't require a fan) and the SSD storage, there are no moving parts the MacBook. It will operate in complete silence.
Pro Display is very good
Everything about the display is very good - from its high resolution (2304x1440) to the brightness (325 nitts), uniform brightness distribution (90%), and high contrast ratio (1000:1) with over 95% of the sRGB spectrum. Overall, this is a very good display.
Pro 3D Touch Trackpad
Pro Fantastic clicky keyboard
Con Connecting more than one thing requires a hub
The laptop comes with a single USB-C port that's used for charging as well as any other peripherals or external storage devices. Connecting more than one thing at a time requires using a USB hub.
Con Keyboard is very shallow
The keys are not as firm as the keys on the MacBook Pro or MacBook Air. This can lead to more typos, and less comfortable typing.
Con Not very powerful
With an Intel Core M processor, the 12" Macbook isn't a serious development laptop. While it will get the job done for lighter tasks, it will struggle with heavier jobs.