I've been using my Smart for close to a year and love it. It is a little tricky to use the first time you belay a lead climber (buy your partner some brew afterwards), but with a little practice, it's an amazing device. The only real drawback is not being able to repel with it. I saw a teaser photo of an "alpine" version - one that can belay with 2 ropes - a while ago. I wonder if it will ever be produced?