a bit further a field, B14's are starting to play with carbon RDM's. and they reckon the wind resistance is also a fair bit less. and the stiffness is still there but can also be tweaked. don't know if the wind resistance on a wave board is such an issue but...
in saying that i've got a north needle, whichis a RDM with a standard base so you get the stiffness but you can use a standard extension

. i highly rate. but yeah all comes down to feel in the end and what you want.
poley