I have had one in my tank for about a month its quite large with 3 actual cups the middle being vertical. It is doing great and all the heads open up fully. It is very easy to take care of as long as you have good calcium, good lighting, and lots of flow. This coral loves light, but I found it more sensitive to proper positioning in tank to get a good alternating current on it.
That being said it is one of my favorites in my tank, I have it next to my huge metallic Gonapora (don't remember how to spell it), and as a side note both are doing outstanding with my T5 lights.