i ride an 09 fuji roubaix pro. its alu frame with carbon seat stays and fork. i chose it over a cannondale becuase a roubaix based bike is much better for the crappy country roads i ride on. its a very smooth ride, but i dont think id use it to race on as its not as stiff as other frames. its a great climber.
ive replaced the saddle, even though the origional was just fine, just wanted a bit of bling. i also replaced the seat post, stem and bars for some carbon.
my only complaint is that it would have been nice if it had come with a shimano crankset instead of the FSA. the FSA is fine though and it did keep the price down.