Originally Posted by Dancing Skeleton

These things are not gimmicks.
I test rode my Madone 4.7, a Madone Six & a Domane Six, all with the same wheels, Ultegra on two of them, Force on the other. I took all three bikes on the same loop, with hills, bumpy & smooth roads. The difference was very noticeable. The Domane had the best combination of handling, responsiveness & ability to absorb vibrations was far greater than on the other bikes.
Liked it so much that I ordered a Project One.
I really notice the difference after three hours in the saddle, and even more after rides of 75+ miles.