Sand or Fluval?

[Pro Fish Keeper]

Im about to start a 90 g reef tank. I hope to have tons corals and live rock. A good sized reef. I have some experence. I was told that sand beds will (in the long run) create the natural effect. Everyone I have talked to so far said their corals and fish thrived in the sand tank. Using about 300-400 w of lights 30-60 pounds of rock 4-6 maxijet 1200's, maby a sump, with a uv and protien skimmer. With maby 4 inches of live sand. I like sand better then crushed coral. Im just wondering which is more effective,if i still need to mechanicaly filter my tank and which is easyer.