I think, Robi's boat was the prototype (or at least the first US built Blade). All the other Blades that I have seen (US VMI built Blades) have the rotation below the boom. It does not seem to pose a problem during tacks/gybes. The rotation controls run through a grommet on the tramp and out to the main beam to a cam cleat on the hull. It works ok for me, but can be a hassle when in 1-up mode b/c the controls are run forward (this could be easily addressed if I were not so lazy).