Sand has it's advantages, such as it's looks, low cost and the fact it's most natural for fish such as corydoras. You'll notice corys will have nice long natural barbles when you use sand, where their barbles will wear down on bigger/chunkier substrates. Also like said, poop and whatnot tends to just sit on the surface, which is nice. To me, that's where the advantages end.
Sand requires a lot more attention during water change time so you don't disturb your decor. It does suck-up easily during vacuuming and if you run HOB filters, you have to take precautions (pre-filters) to prevent your impellers from being destroyed. Most canisters have the impeller on the clean water return side, so sand will just sit in the bottom of the canister and not be an issue. Sand is a lot more labor intensive (messy) the day you want to break-down and re-do your tank as well. I can shop-vac out a tank with gravel in minutes. Sand? Not so much.
FWIW, of my 4 current setups, 3 are gravel, 1 is sand.
