Actually a recent study has found hat the FES propeller has a significant, measured impact on performance (2-4% depending on average flying speed). The FES should have a considerable handicap over pure in, for example, the Lak17a or b with FES vs non FES. The US handicap committee has done nothing to address this. Smells funny to me. Clearly a big propeller in the nose airflow is not equal to not having a massive propeller? Only thing for sure is THAT IT IS NOT THE SAME PERFORMANCE. Yet the handicaps are the same?