Some species are more difficult to keep than others. In order to keep them you need to feed them, target feeding is best. Some of us do manage to keep them long term. My tank is heavily fed (cyclopeeze, freeze-dried rotifers, different sizes of golden pearls are target fed to them, plus I feed heavy to the fish). But...I run a 100micron filter sock continuously, have a skimmer larger than I need for my tank, run carbon and phosban in phosban reactors, and have a very large mass of chaeto in the refugium portion of the sump (which provides nutrient removal and growth of zooplankton). If you are going to feed the gonis heavily and still try to keep acros and keep nuisance algae at bay, you need to filter. Some keep gonis and don't filter heavily, but I couldn't make that work and still keep acros. Now my gonis grow, and my acros grow.
Having said that, they are not beginner's corals, and they have a bad track record. But possible to keep if you are willing to put in the time and effort and set up a suitable environment. A low fed tank is not a suitable environment (IMO).
There is some great info about them by JeNnKerry, justincognito, and John Kelly here on RC.