I bought a Roubaix explicitly for the futureshock as I have bursitis that vibrations through the handlebar exacerbate. I wasn't disappointed, the futureshock has helped immensely. It works best at certain periodic frequencies. As an example, there is a bridge on a downhill with slats that would vibrate my carbon gravel bike's bars so hard it would nearly wrench them out of my grip. The Roubaix just glided over them. I guess they are at the same frequency as cobblestone
Anyhow, not a gimmick, but not for everyone.