Beardie substrates are highly debatable. It is your responsibility to do as much research and get as much advise as possible on the best ways to care for your lizard, because you're gonna hear a lot of different opinions and scenarios and you have to make informed decisions.
That said, here is my 2 cents....
I've seen plenty of people say they've had no problems with sands. Then again I see just as many who have had problems. I've seen a beardie at my vet's office that was impacted on calcium sand, it was not pretty. The way I see it there will always be people who haven't had problems yet and possibly never will. There is a first time for everything though, and many lizards have died from sand impactions. I figure, why take the chance at all? I keep my both of my lizards on non-adhesive shelf liner and paper towels in the places where they usually go to the bathroom. It may not look as fancy as a "natural looking" setup, but I don't care. It is a possible risk that we've all heard about one way or another, and I'd rather heed the warning now than be regretting it later.
If you do choose to use sand when your beardie grows up, there are still ways to greatly reduce the chance of impaction. They can easily get mouthfulls when hunting crickets or kicking sand in their food dish. If you take him outside of his cage to feed crickets, and put his veggie dish on a section of the cage that isn't on sand, like a raised platform, it helps a lot. I would still not recommend any calcium based sand, it neutralizes the stomach acids which slows digestion, and this is what can make it very dangerous. It's also ridiculously overpriced. Playsand bought at Home Depot or Wal-Mart that is washed and sifted I hear is much easier on the beardies' stomachs.
Personally, I still like paper towels and shelf-liner. Cheap, easy to clean, and 100% impaction free. 
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2.0 bearded dragons (Ocho / Domo-kun)
0.1 kingsnake (Rio)
1.0 ferret (Playstation)
1.0 cat (Wally)
0.1 dog (Tima)