I've deployed a dozen macbook air's in this office, they're great and dead simple for people to use which makes my life easier.
If it was more than 20, I'd move to windows and set everything up properly, because OS X deployments are a nightmare to manage for businesses.
The quality of the hardware is good, but the after sales support is meh... Can't just walk into a store, need to make an appointment, need to leave it to get checked out (and can't remove hard drives from the laptop first), need to wait for replacement parts to arrive, etc... Sorry, I can't have a user to be completely without a laptop for 2 weeks while it gets repaired.