Weight modification factors make sense. The game is Horsepower to weight ratio and drag. Heavy sailors don't have as much Hp/weight and they have more drag! If you want to play fair, then you should use weight modification factors.

The International F18 Class Rules seems to have corrected for this better than anything I have seen prior. If you weigh less than 308 lbs. you use smaller jib and spinnaker. Weights are corrected for by adding 1/2 lb. per lb. underweight the skipper and crew are. It is working in our club and we have several crews using the smaller sail plan. In this class, two women would have very good chances of being competitive with two men, even when there is significant weight differences. This situation does not exist in most classes (other than the Nacra F17, which has large and small spinnakers and weight corrections to minimum similar to F18).

Just my opinion. BTW, the N20 is very powerful and big crews seem very competitive on that platform. This is not the case for most catamarans.