IMHO, sand beds, especially deep ones, offer a great deal more food for SPS corals than any bare-bottom tank can. But, as always, there are a lot of factors.
Clearly, there are many ways to setup a tank and no one way is "correct". However, there are ways that are "better" than others. I count DSBs as better than wet/dry filters. That is a far as I will go.
-Tom