roubaix is more upright seating, longer head tube, harder to get down low to beat the wind to draft. The madone and foil will be more agressive fitting but we also have long arms to help w/ that when in the drops. The pinarellos are pretty aero too. Lower end Prince /Gan usually same molds as higher F series bikes w/ non hi mod carbon.
I have an older Gan S that is same mold as the F8, but the whole bike was a lil cheaper than F8 frameset. 10k miles later it's still a rocket, 6'1 and ride 56cm. 565mm top tube plus laid back seatpost. Geo works well for me.
