El Capitan on MacBook Air with 2 GB ram I have a MacBook Air (MacBookAir3,2) with 2 GB ram and still running Snow Leopard (10.6.8). The App Store offers me to upgrade to El Capitan, so I guess the MacBook Air is still supported. But I wonder if you can really enjoy El Capitan with only 2 GB ram? 

The reason why I think about upgrading at all (beside security issues) is a new iPhone that won't sync with an old iTunes.
The official system requirements from Apple state 2GB of RAM minimum. And as you have flash-based storage the paging to disk that many people see running RAM hungry apps will not be too bad. With any luck.

However I would be hesitant to recommend it as the newer the OS the more RAM hungry it seems to be. I would make a disk image of your current drive somewhere safe (external USB drive) so you can restore it easily if you don't like the results.