I just got my first RFA from a vendor based in Ohio called Frost Corals, they were posted about before just a page or two ago. They were at Aquatic Experience in New Jersey recently.
I placed my RFA on a rock like the vendor told me, but I didn't look too close at the rock itself, I just wanted to put it in a somewhat low spot away from corals and things that might bother it, only it's really sunk into the crevices. It's fairly small, maybe the size of a half dollar, I got it last Saturday and so today I fed it a bit of fish, it was still eating it here. It readily took it and it's nearly gone now so I'm taking that as a good sign that it's happy. I'm really excited to get more!