Kid Epic Wyoming wrote a review of Mammut Smart Alpine Belay Device - 8.9mm-10.5mm on October 10, 2011
Rapping, guide mode belaying, this little baby slays it. I wasnt very impressed with how it work with a single rope. The rope would occasionally get caught up under the friction panels. Other than that, its pretty sick working with a double rope belay, rap, and guide mode.