I'm split. I have a 2011 Air that I rarely use. The 4MB of RAM and slower CPU is the major problem with it; screen resolution is a distant third. I keep thinking of buying the most modern USB-A-and-SD-card-reader-equipped AirI can find, because it truly is the best machine I've owned.
On the other hand, new and shiny! And I almost never use the SD card reader or USB port, it's just nice to have. And the keyboard is fantastic.
Other than the outdated display, performance is perfectly adequate, and battery/trackpad/keyboard/SSD speed/ports are still doing great.