One thing that wasn't brought up though... If you have one of those fish tanks where you have to scrape the glass due to algae, you will be very pissed at the sand over time. Sand will get under your scraper and put a huge scratch in your glass eventually, if you scrape often. This type of problem would really be frustrating if you are forced to experience it.
Sand is pretty heavy outside of a fish tank, but at the very bottom of your tank, the sand kind of flows like a liquid. Also, things accumulate on top of sand that you normally don't see with a larger substrate.
Just my 2cents before considering this for a substrate if you haven't tried it before.