I picked these up last season to use with a board I had bought. I wanted something with good support, good response, yet wasn't excessively stiff. I have a lot of Burton bindings, including the C60, Diode, and X-Base, so I decided to go with Burton again.
The hammock highback system seems to work very well without any issues, and offers good support. The straps are big and comfortable while keeping my boot secured to the binding. Like I wanted it offers good response without being overly stiff.
The only issue I have is the Re-flex system over regular discs. It doesn't really feel that much difference to me, so I don't think anyone should choose these for this feature alone. I have a lot of EST bindings and those actually feel different. This one doesn't.
Overall I would definitely recommend these bindings to anyone looking for a solid item. I love it enough that I'm buying the 2014 EST model for a new board of mine!