I've used it. It seems very much the same as Caribsea's Arago-live. It's really not a true live sand replacement. I believe what they term as "live" is simply the presence of bacteria. Personally, I didn't see any benefits using either of these bagged "live" sands and would prefer to go with regular dry aragonite. It doesn't take very long for you to seed it with bacteria anyhow And these moist "live" sands should have a limited shelf life, making it a concern to me about them going bad if you get an old batch.
I used that stuff to set up my first tank. I can't say that it hurt anything, but I don't really think it did any good for the tank. The stuff I used said "No need to cycle! Just add fish!" I usually tell people not to use it.
I see no benefits to using that stuff over "dead sand" and the fact that it gets shipped and sits on shelves in stores for... who knows how long, says a lot to me about how "live" that "live sand" really is.
If you want some help starting your live sand bed, ask a local reef keeper for a scoop of their live sand to seed your sandbed with. Use plain old dead sand to fill it in. Over time, the scoop of live stuff will reproduce and give you a *real* full blown live sand bed.
You don't *need* to do this, but it will give you a nice boost. Live rock by itself will also do the job for seeding your sand bed nicely.