I would always recommend a MacBook. I used to always stick with various non-Macbook laptops (Sony, Samsung, Lenovo, etc). I switched to a MBP a few years ago and don't think I can go back. Have bought 5-6 different MacBooks since.
I own a mid 2012 MBP (16gig ram, ssd, retina) and really want to upgrade pronto.
This. The MBA is fine for most things I do; in fact I prefer a slower CPU if it gives me more battery life. But the screen is so bad I regret getting the MBA anytime I look at a different screen, including phones.
edit: however, I recommend the MBP. I've only had bad experiences with Linux on laptops, which I have to use for work. HiDPI sucks on Linux. You'll get conflicting advice, most of which is useless because maybe the person telling you <Linux dist> is the best" really likes tweaking <Linux dist>.