My Xenia Elongata grows a little too rapidly for my taste, it requires regular pruning and it seems to find its way around everywhere in my tank. I'd rather have the Red Sea variety.
It does great in a tank with softies. I don't have any, because I have a sps dominated tank. I don't trust softies and hard corals together.
Good luck.
My xenia grows like wildfire, but I wouldn't set up a system without one. With this addition about six months ago, my skimmer pulls out less and my macro grows really slowly in my refuge. I consider that a good sign. Nitrates have dropped out of testable levels. Pulling the smelly stuff once and a while is a small price to pay for all it does.