Clayton wrote a review of Mammut Smart Belay Device on April 18, 2012
This is a truly awesome belay device. I am a very light weight climber so most of the people I climb with out weigh me. I always found myself struggling to maintain good rope control and break control when I belayed with a traditional ATC. I heard a lot of good things about the GriGri but when I was first starting to climb I didn't want to spend that kind of money. So I decided to give this a try. First time using it I was astonished at how well it worked and how much easier belaying became for me.
I constantly get asked now wherever I am climbing "how do you like that device?" My response is always an instant "I LOVE IT". The only complaint I ever had about the Smart is the inability to top belay from an anchor. Because of that I have since upgraded to the Smart Alpine but can't stop singing the praises of the Mammut Smart devices.