I'm not going to agree or disagree with the above, since I know nothing about MacBook Airs.
Apple made a massive way to the way their laptops sleep around 5 years ago, so I made this .txt file that explained the changes made several years ago. I don't know if things have changed again, but you can easily switch between sleep modes.
Old PowerBook and iBook sleep mode = 0
To change to this sleep mode, command (in Terminal): sudo pmset -a hibernatemode 0
(hibernatemode 0 is the one I use)
The state of the computer's OS and all software is stored in your RAM when you're using the computer (i.e. Computing 101), and this is the way it remains when in Sleep Mode. Your computer just goes black, but the RAM is kept alive and running. Putting your laptop to sleep is fast, and so is waking from sleep. Unfortunately, if the laptop is asleep for too long and it runs out of power, you will lose all running apps, documents you were working on and didn't save, the song you were listening to on iTunes, etc. This is because the RAM is cleared when there's no power. The next time you connect your AC adapter to your laptop, you'll need to boot-up again.
MB and MBP "Safe Sleep" mode = 3
Command (in Terminal): sudo pmset -a hibernatemode 3
When you put your computer to sleep, your RAM is powered and kept running, so all your running apps and current computer settings are still in your RAM (just like the method I described above), but its also copied to your HDD/SSD so that if you run out of battery power, the previous state of your laptop is still on your HDD. Of course, the data stored on the RAM is gone since there's no power. Waking up from sleep is fast, but putting your computer to sleep is slow because things need to be saved to the HDD first. When going to sleep, look at how much more time it takes for the blinking light to start pulsating. If you run out of power, then the next time you plug in the AC adapter, the state of my computer is restored.
Sleep Mode = 1
Command (in Terminal): sudo pmset -a hibernatemode 1
In this mode, the system ONLY copies your system's state to the HDD, not RAM. Your system's state is moved from RAM to your HDD, and everything on your RAM is wiped. Actually, it's just not powered while your computer is in Sleep mode. While your computer is asleep, RAM is not being powered (which is the case in Safe Sleep (mode 3, above). Of course, waking up from sleep is going to be slow, as is putting your computer to sleep. But if you want to save power, this is the best way to do it.