I agree with Kingy.
I think it is poor that people are recommending going to another class just because we are asking a question! We are investigating an option to get more people into the class, not repel existing members.
Square tops are a subject that has been considered in the past, they are a development that other similar classes to ours have gone with and certainly something we should at least rationally talk about. My understanding is that Mozzies are scaled down Tornados, and square tops are something they adopted many years ago.
As our state and National results illustrate, the better sailor will always beat the better boat within our class. Most competitive sailors update their sails every 5 years or so, and the sail should cost the same but be a different cut. The only changes the Arrows made to their rig was a shorter boom and lower or adjustable gooseneck. If the existing boom was modified then the costs would be minimal, as are the increases in performance, however the modernised look would make a big difference to updating our class.
Perhaps before this becomes too much of a hot topic, we should get some details from the South African mozzie with a square top about what is required to reduce the conjecture and allow us to make an informed decision.