I think Travis hit on one of the biggest benefits of a DSB environment in a reef tank. It has to do with micro-life. The addition of a DSB simply adds so many creatures from nature that you would otherwise just NEVER see. They provide a means of natural filtration by breaking waste down to more and more minute particles, they provide a natural food source for our fish and corals, they offer us a glimpse of the ocean depths right in our living rooms. Without a sand bed, most of these points are lost when trying to keep a reef tank. And yes, it IS more asthetically pleasing than a bare glass bottom, IMHO.
However, as everyone knows, there is certainly more than one way to skin a cat. This just happens to be my preferred method
To each thier own, and I'm sticking to that story
Cos