I put the DuraAce derailleurs, brakes, shifters, cassette, from my Blue to my Madone. I also put on my Mavic Ksyrium wheels. That being said, the components and wheels that came on the 5.1 re pretty good, and the Blue rides nice with them. I just prefer the ride with the DuraAce components.

I actually LIKE the seat that comes with this bike, and left it on.

Enjoy!