Funny you should ask. I just posted an update on our goni in my tank thread this morning.
I gave Christy a lot of grief for buying it, thinking it would be hard to keep alive. At first, it wasn't very happy in our tank. Polyps were open, but not extended. I noticed some recession around the edge, and I didn't know if that happened before or after we bought it.
I moved it to a lower flow location in the tank, where detritus has a tendency to swirl and settle. The goni seems to absolutely love it here. Polyps are now extending out from the base on their stalks, and tiny new polyps are starting to appear between the large ones. It even appears that the tissue recession has reversed. Here's a closeup I snapped this morning:
I don't target feed, and the water in our tank is about as clean as you will find (our tank is BB, high flow, has a fairly light bioload, and is skimmed heavily). I don't target feed, but the goni seems to be finding plenty of food. We've only had this one for about two months, so I can't claim long term success, but things are looking pretty good at the moment.
Also, I've been told that red goni's are the easiest to keep.