They're very friendly (once you spend time handling them), mine (even though I got them at around 6 months of age) are willing to eat out of my hand, and when I approach them, they don't run away or go hide as I've heard some other quail have done.
They only fly away when a bird flies overhead and pretty close, or if a bird perches near by. That's only when I let them free range.
They produce lovely, tasty eggs and apparently tasty meat as well (I don't eat quail meat >.<).
Coturnix quail are more commonly used for egg production and meat production in commercial businesses anyway.
And I love them!