I would mount it 20mm forward to allow some versatility in binding position.
Michael:? Maybe you already have, but I would do some research before mounting the CP13 20mm forward.? The setup on my i.SL Chips is the CP 13 plate with LD12 bindings.? I asked jbotti to do some research and he asked Harald/Diana and their recommendation was to stay with the default mounting position with the CP13.? After skiing it last year, I would agree, although it's hard for me to know if its the plate or the ski.
I surmise that the CP13 plate does a better job of projecting force forward (especially as the the ski flexes) than the railflex.? With the railflex, the force is just weight pressing down on the rails.? With the CP13, the front plate seems like it might distribute the weight better and the rubber damping bumper under the toe of the plate would compress and increase forward pressure as the ski flexes (sort of like the piston arm on the Marker bindings).
Anyway, Harald/Diana's general recommendation was +15 for railflex and factory mount for the CP13.
By the way, I think the SuperShape comes with the CP13 carve plate as well and I don't hear anyone having problems with the mounting position or any discussion of moving the plate around.? Ron??