More saddle setback favors the glutes and can make for more power and better endurance due to using more muscle groups.

Less setback gives more open hip angle, & favors the quads, & higher rpms.

I was passed by (& kept up with for a while) a fast group yesterday- mixed ages & genders, but they pretty much all had a long, low set up, lots of setback, & long stems.

This (the sanctity of saddle setback?) is a subject of almost religious conviction for some, that there is one perfect, yet mysterious setback.