We have a 75g with 6X54 T5 in individual reflectors. It is a very tight fit, but the tank is an LPS tank with some softies. Everything in the tank grows like crazy. Some of the LPS are high in tank, just need to acclimate them to the high light.
This tank is at my girl's office and she takes care of it. I am not sure the current bulb config, but I believe it is 3 actinics and 3 60/40s. It is mostly personal preference, though I believe that growth is stimulated more by the yellower light, while the bluer look makes the colors really cool. We also have 3 clams in this tank, 2 croceas and 1 maxima. They have all grown a bunch.