i say try out sand, i much prefer it to gravel - not only aesthetically but also because many kinds of fish/inverts like to burrow in the substrate and sand allows them to do this easily. Also, sand doesn't hurt the barbels of loaches/catfish. The sand I have is fine but heavy so that my siphon can go through it and not suck any of it up out of the tank. In general detritus will accumulate on top of the sand, and you can just siphon it out.
The only thing with sand is that gas pockets can form in it unless it gets disturbed periodically, which is why I would recommend putting malaysian trumpet snails in a tank with sand substrate.
