Some need intense light to keep their coloration, others prefer more protection. Generally, a happy Favia will inflate it's tissue quite impressively when it's in a place it likes. They sometimes look like the tissue around the perimeter is melting like candle wax.
I've found growth rates on mine are much faster when they are placed on smooth pieces of rock than when they are placed on sand. I've had some calcify and attach to rocks in a matter of a couple weeks when left undisturbed.