I have to say the seat post geometry seems to make little difference to me my position seems to stay the same in relation to the bottom crank. The saddle is just set further back or forward to keep that relationship. The Super Course in my case has a bigger frame by miles and the Corsa is a tiny 19.5" frame, the Giro is 21.5" so nicely in between the two. The Corsa is very comfortable the Super Course is slightly more stretched out but still comfortable. While the frames are different sizes the reach is not so different the stems are similar length but the tops of the bars on the Corsa project forward a good deal more than on the Super Course. The bars on the Super Course are much wider than the Corsa. The Giro's bars and stem and top tube are all closer to the Corsa, but as both the others are great to ride I am sure this will be too.