I think a tank looks incomplete with no sand on the bottom, It personal preference I like a sand bottom.

I'm a bare bottom guy.
With the right flow and a good sump/skimmer, I think your regular eras of neglect can go longer with less reprocussions! On the same note I believe a sand bed brings some nutrient instabilities if they are disturbed or not taken care of
AND there are no scratches on my glass.
On the flip side there are some fish I would like to have but wouldn't even consider because I'm bare bottom.