I would turn to the absolute authority on the topic, Bob Goemans: http://www.saltcorner.com/sections/g...dbedspart1.htm
You should take the time to read this, and then click on the link for the 2nd article, at the end of the 1st.
I have personally had great success with DSB systems, and not so great success with the Jaubert style plenum systems. I think a lot of the bad publicity you may hear comes from people who do not understand the different in care, and attempt to treat the DSB like a plenum.
The topic is extremely complicated, hense the article link. However, I will point out a couple of personal experience bullet points.
First, you need a minimum of 3'', and will probably have better results with 4''. I personally use 4'' of aragonite sand.
Second, you must have a significant number of sand sifters. Starfish, nassarius snails, hermit crabs, etc. I recommend 1 sifter per gallon, as a general rule.
Third, you NEVER disturb the sand. You don't vacuum the sand at all, not even the top 1''. This is a point of clarification and difference from a plenum system.
In any case, i am not an expert on the topic. In fact, there are very few experts on this. Almost every article you read is a summary of something Goemans has written or achieved. So, click on the link above.