Shimming C and A's

[rindtj]

Sounds like just about everyone agrees they need it, but my question is if I shim the skis, what is the affect on the C and A rubber stopper involved in mounting? Do these wear out in a year like the Yamaha mounts? Probably a lot more problematic to get C and A mounts then paying 5 bucks form the dealer? What have you guys found? Better rubber on the C and A mounts? Different material to shim with? Planning on going with these skis but I don't want to pay 35 bucks a year for the mount kit because the rubber is shot.

Thanks