As the long-time Mac user, current owner of an
11.6" MBA ("my favourite laptop ever"), and someone who considered buying a
12" MacBook as early as last week (but would have waited for the next update), I'd still recommend the 11" MBA. The biggest differentiator is the Retina screen of the 12" MB, which isn't a big deal to my eyes. Sure, the MacBook screen is sharper, but it's not like the 11" MBA's screen isn't sharp. The sharpness is fine, even when compared to a Surface Pro 3, which has a screen with a "Retina"-level PPI. I have both a Surface Pro 3 and 11" MBA sitting in front of me, and I'm looking at the same photo on both screens. Trust me, it's not a massive difference.
Having said that, I'm not extremely sensitive like some people are!
If there's anything about the 12" MacBook's screen that I'm jealous of, it's actually the colour accuracy and contrast, which is difficult to judge objectively simply by looking at a photo. For the significant majority of girls and boys entering highschool, neither of these are a big deal at all. What's important is portability, battery life, keyboard and trackpad comfort, and ease of use. I think the 11" MBA covers all this pretty well. That, and it has ports!!
The only reason I had considered buying the 12" MacBook is because I feel the 11" MBA is a poor deal when considering the level of equipment you get for the price, particularly with the screen it includes. Yes, the 11" MBA is my favourite laptop ever -- even better than my old 12" Powerbook -- but Apple really should drop the price to something that reflects its equipment level (+40% margin, as usual).
The 12" MacBook is fast (in bursts, not for continuous 4K video editing or anything of the sort) for its size, and has a great screen. The only reason I didn't buy one last week is due to the lack of ports, which I already knew about. If the damn thing had
TWO USB-C ports, I would have bought one after the next upgrade.
Instead, I'll probably buy a
Surface Pro 4 because I really like my SP3 at work.