When you're rolling smoother, you're rolling faster. And regardless of if you're on the cobbles of Northern France or the chip-and-seal of your hometown, you'll benefit immensely from the Roubaix.
The "suspension thing up front" also called the "Future Shock" is essentially a piston in the head tube with 20mm of travel developed in partnership with McLaren Applied Technologies, and the result of this is a host of drastic performance improvements, namely in the vertical compliance department. Without giving a physics lecture, vertical compliance, instead of fork splay, meant a massive improvement in smoothness, speed, and comfort in one fell swoop.
And of all the bikes that we've tested against the Rolling Efficiency Model, the Roubaix outperforms anything on the market.