I understand both points of view on this issue, but think that if you are going to get parents and more particularly yatch clubs and kids racing programs involved and "buying" into it, OD is probably an easier sell than a formula approach. The Tornado itself is still a development class, just with tight restrictions as to the development progression. The hull shape is closely defined, but there is around a 5-10mm varience that can be used to alter the shape and performance of the hulls. As to the fact that 99% of the boats raced are from one builder, it is virtually OD. Back to the point though, OD for class development is an easier sell to youth programs.