I have all types, rib, rifle and ghost. For me Ghost is the slowest and least accurate. Just not as instintcive and takes away from the real speed of a shotgun. Skeet with a rib is about as fast as shotgunning can get, and no one ever came up with the need for ghost sites on the skeet pad.
I bought a benelli nova with ghost sites thinking I needed them, they work, but I should have saved the money. When I use the nova in tactical shotgun matches, I seem to miss more then when I use my M1s90 with rifle sites.
I think the ghost sites are an adaption for rifle guys who resist or do not like shotguns. It makes then feel like they are shooting a rifle. So, I suppose for a pure rifle guy, the ghost and post setup feels good. To me, it ruins a shotgun. But I learned how to use a shotgun on a 20 ga double when I was 10, so a rib is more natural to me.