RE: North Sails "One mast fits all" concept.
I'll second what Roger & Ola have said, from a personal experience. I've used 460 mast + carbon extender with a 9.0 Daytona. It will work (well sort of), but when I tried it with a proper (longer/stiffer) mast, there was a world of difference. So, while it may be a good idea (to buy fewer masts), it doesn't offer good enough performance, not even for recreational sailors.