I think another aspect to take into account is control. I persoanlly will go faster if I feel controlled. I put a hole through my 6.6 last season ( my normal "bread & Butter" sail) and had no choice to switch down to my 5.8. My next few sessions were a lot faster because I felt a lot more controlled (was in chop). I think I would have potentional to got "faster" on the 6.6 but I probably would have backed off slightly. The 5.8 was not "fully" powered up but I could keep the pedal down the entire session...
is there anything i can do to my rig to suit my weight better except the usual depowering with downhaul and outhaul? ive heard of people shaving battens to give greater twist but im not sure if this is just a wank or not
I would've thought that shaving battens would introduce more fullness into the sail, not more twist?
I have heard that Slowboat shaves his battens on some of his Koncepts, not to depower, but add power.
You could also try using a softer mast which will add more twist and make the sail more forgivable.