Bare Bottom has one positive thing in mybook, ease of cleaning. If you are doing a fish only tank I would think thats a great choice since you will have more fish and have a need to clean up after them alot more. If you are doing a reef, well,when was the last time you looked at a reef in the ocean and saw no sand?? The aspiration of most reefers is to mimic a slice of the reef and personalize it to your own liking, but there are some basic elements needed. Rock, sand, water,coral and some fish. There are other positives, a place for life to flourish, hide and reproduce as well the sand being alive and being a natural filter. You are going to get lots of opinions, but ultimately the choice is yours.