MacBook Air 2016 from 2012 version

Hi
Battery in newer model is better
slightly better CPU & GPU
much quicker SSD
less power consumption in newer model because LPDDR3 and more efficiency CPU
thunderbolt 2
WIFI with AC

also 2016 model is same like 2015, but 2016 is offered only with 8GB RAM

 

The most significant upgrade will be run time that approaches twice the 2012 MBA. The 802.11ac wifi is also really nice, if you have a router that supports it. It is something like 5x the speed of the wifi on the 2012 model which makes a huge difference working big files on local network drives over wifi. Would also be noticable if you have a really fast internet connection such as FIOS.

The SSD is certainly faster, but I think the only significant difference is with the 256 and 512 models, not the 128. But it depends on how you use the machine, many people would never notice the difference. And unless you do the things I mentioned above, you probably won't notice the improved wifi speed.

But anyone should notice the difference between 6 hours and 12 hours run time on battery.

 

Macs have a long service life. If you can afford it, max it at 512GB.

 

I had a new early 2015 MBA and now have a 2012 early MBA. Aside from bettery battery life, there is no noticeable difference to me. I use Safari, photos, itunes, some light games. Feels identical. I got mine used for $440, looks near new. Your call. If you can afford it, go new with warranty. Open box from Best Buy also has good pricing with full warranty or Apple refurbished.