CF guards break down from repeated small hits (the resin).  To the eye it looks fine but the cloth can actually flex.  I've pulled them off to find a dented pipe.  Also, they stiffen the pipe when clamped on, so the header kinks in a hit, and is very difficult to fix.  The only real sound way to implement a pipe guard is to integrate it to the skid plate or mount it to the frame.  For whats available now, that means Hyde Combo.  The R&R totally sucks on the older bikes but a Combo for an '11 fits great on a '12 and the holes even line up perfect with the factory frame mounts!  I made a custom rear mount that captures between the linkage pivot and frame tube and I can have it off in seconds for cleaning or an oil change, so easy I didn't even bother adding a hole.  Foam keeps the mud under control.  I think that when you hit something, it both flexes a little and slides off rather than bites in, so less impact energy is transfered.  I still have the original pipe on my '07, riding in serious rocks.  I have never been able to say that with carbon fiber guards.  Given the choice I'd just buy a $40 Moose bend it yourself alloy guard over a CF guard.