Alex, thanks. This was terrific.
I have a 2011 MBP, which I'd like to keep as a back-up (still going strong!) but have wanted to get a lighter machine, and I've been wavering between the Air and the new Macbook. I determined to get the Air, wait for improvements on the Macbook (figure in the next couple of years) in power and with the one port, at which point I'd sell the Air. A knowledgeable friend assured me that kept in good condition, resale prices can be very good.
Then...then I went to the store yesterday; I wanted to see (and feel) the two side by side. And oh my, my very rational brain went away and all that was left was "pretty pretty pretty pretty."
Your review doesn't make it easier! Except for the fact that I don't like being the earliest adopter in general, and second, I wonder if the resale for the "first" Macbook 12 will not be so good in coming years, as newer models will likely offer more bang for the buck.
Looking the numbers, I ended up with this:
Air:
1.6GHz Dual-Core Intel Core i5, Turbo Boost up to 2.7GHz
Intel HD Graphics 6000
8GB 1600MHz LPDDR3 SDRAM
512GB PCIe-based Flash Storage
Backlit Keyboard (English) & User's Guide
AppleCare Protection Plan
$1748
Macbook 12:
1.2GHz Dual-Core Intel Core M, Turbo Boost up to 2.6GHz
Intel HD Graphics 5300
8GB 1600MHz LPDDR3 SDRAM
512GB PCIe-based onboard flash storage
Backlit Keyboard (English) & User's Guide
AppleCare Protection Plan
$1848
Which doesn't make it any easier!
But thanks again for your well-balanced take. I still don't know what I'm going to do, but I really appreciate your perspective.