Replaced the flat alloy bars on my Novara Big Buzz with generic (performance?) CF bars and was impressed with the reduction in vibration. But, once I forgot how it used to be, it seemed again like a rough ride, thanks to the heavy duty alloy frame and fork. Not as rough as it used to be, but still not a Comfort Bike. Thank goodness.
I have Performance CF bars on one bike, and FSA Wing Pros (Al) on another, and honestly, being a clyde, the additional flex of the CF bars take a little getting used to. Your choice of tires, wheels, and fork all conribute to the amount of buzz you'll feel at the handlebar. On a price/gram scale, Al wins hands down. Something like a Deda 215 bar would be a worthy upgrade. Or you could do what Treespeed says and get wider tires. Cheaper option, would make a noticeable difference.