I'm convinced. Having been the strongest advocate for sand as substrate, I yield 
  
After having tried a tank with, well not BB, but with tile floor, I can definately already see the benefits, and are in the process of converting all my tanks to tile/slate floor. I will keep a handful of sand in there, just to let them show off a bit with the sand spraying. But part from that, no more sand substrate for me.
I thought I had the sand under control, swarming with Malaysian Trumpet snails, but a few days ago I found two little ones sitting dead upon a darker spot in the sand, the babies choose the wrong resting place, one where an anearobic pocket had formed. They simply suffocated. I could smell rotting eggs when I syphoned the sand out.
The slate bottomed tank proves so easy to keep clean I can't believe it. And the fish seem to thrive with it too. 
So, still not 100% for BB, for estethic reasons  

 But tile/slate floor - 100% in favour.