Brian Clark wrote a review of Black Diamond O2 Telemark Binding on December 10, 2009
I started tele-skiing on old 3-pin mountaineering bindings and Ranney Super-Loops. Moved up to the G3 Targa when they came out. I have been on these for 3 years now and could not be happier. These were a great step forward from my previous bindings and I immediately saw an improvement in my control at speed and when turning in the steeper terrain. Depending on what your boot/ski combination is (especially if you are on fat skis w/big boots), you might want to spring for the rid-stiff cartridges.