The key to comfort on the CAAD9 (or any stiff bike) lies in tire/PSI selection. With 28's at 70psi (totally personal), My crit bike rides every bit as complaint as any carbon/steel/titanium bike I have ridden. I have plenty of back to back 100+ mile days to back up this claim. As for the seat, again it's personal preference. I use the same seat that I always ride. My butt and the sella italia flite are long time friends.