Pred man, I agree about softies but Xenias are pretty delicate and require near perfect conditions. IMO, I wouldn't start with them anyway.
Anyway, I am happy to see this thread. This exact question has been bugging me for weeks. Many a moon ago when I worked at an lfs, I *swear* we would start with some hardy corals sometimes after the water had stablized. But my memory is foggy and I haven't been able to confirm it yet.
I am interested to hear what others have to say. I hope to add what I find out from my old boss, hopefully soon.