Good write up Paul. I agree (but don't do all) with everything except the part about prebend. Maybe I do not understand the function of prebend.

I agree that flat sails are fast. Doesn't prebend flatten your sails out before adding any downhaul/mainsheet tension? It seems like my mainsail was/is too full and creating too much drag in light air and I cannot downhaul enough in heavy air to depower. I've added some more prebend (spreader rake and daimond tension), but not had a good chance to check it out.

Wouldn't it be advisable to follow the individual sailmakers opinion on prebend to get flat sails? and to take into account your crew weight?

OR - have I totally missed the point of prebend?