Kevin J.wrote a review of Mammut Smart Belay Device on August 10, 2013
Familiarity: I've put it through the wringer
One thing I've noticed other reviews missing is how much better it is for catching falls on trad lead. Since gri-gris stop so instantly it puts a lot more of the shock on your protection, whereas the smart gives a little slip to help ease it. This is a great help when your last piece was sketchy or you're ice climbing.