I've got a Specialized Roubaix Pro frame now, because of a warranty with the original Comp frame I bought last summer. The 2d week I had the Comp, one of the water bottle screw anchors in the carbon frame came loose. The dealer said Specialized gave me 2 choices--let them epoxy the the anchor back in because it wasn't structural and they agreed to send me the new, more expensive frame at no charge. It was a no brainer.

I can't tell that those inserts do a thing. It is probably either a gimmick or such a slight difference that a normal human being could not perceive it.