Unless you need a higher screen resolution, I'd recommend buying the Air. I'm guessing whichever replacement for Air they come with will be similar to Macbook 12" which are new and cool and all that, but that's mostly it.
- The Macbook Air has a separate SSD on it's own board. If your Macbook dies, you can pull out the SSD and get the data off it. (I still recommend backing up your files.) And if you want to upgrade to a bigger or faster SSD, you can buy a new one from OWC and put it in. Newer Macbooks has the SSD soldered on the motherboard, which means if your Macbook dies, your data dies with it. That also means the storage capacity you buy your new Mac with, that's the capacity you get, and that's what you'll have to live with.
- The Macbook Air still has a fan to cool down the CPU. The newer Macbook Pro also has a fan to cool down the CPU, while the Macbook 12" doesn't and instead is using the whole bottom plate to cool itself down. That means unless you're Linus, you'll experience a reduce in performance due to the computer slowing down to prevent overheating.
- The Macbook Air has the battery screwed in. I'm sure not even Apple replaces the battery, but will give you a sky high price for replacing the top case, and tell you to buy a new laptop instead.
- The Macbook Air still has normal USB ports. The newer Macbooks has only USB-C, and Apple's intention is to switch the entire electronics market into using USB-C, which I believe is going to take a couple of years. And while you wait for that to happen you'll be carrying around a few adapters. Also, having a very few ports do everything means these few ports will be plugged in and out a lot, which can cause them to wear out faster. But at least they still has a headphone jack.
So, is there anything good about the newer Macbooks? Yes, there is.
- Macbook Air 13" only has a screen resolution of 1440x900 pixels. (The 11" which isn't sold anymore has 1366x768) The Macbook 12" has a IPS Retina screen with 2304x1440, and the Pro 13" has 2560x1600. That means space for more stuff on the screen if that's something you care about. I really wish my laptop had a higher resolution.
- The newer Macbooks uses the USB-C for charging. If you lose your power adapter you can still charge it from another USB charger in an emergency, even though it goes a lot slower than with the original adapter. The Macbook Air is still using Magsafe. The idea is that if you stumble on your charging cable, it will just pull out of the connector rather than the whole computer hitting the floor. How useful that will be depends on how clumsy you are.
But in the end it's your money, and I'll let you decide what to buy.
<Edited by Host>