I agree with others that road dampening quality of carbon bars of aluminum is either minimal or non-existent. The only advantage I can see for carbon is bling, if you are into that and that they can be shaped more ergo than aluminum. They aren't necessarily lighter either.

Same is true with seatpost, I pref aluminum over carbon. Aluminum is as light if not lighter and it doesn't scratch like carbon. So, the only seatpost I will use is Thomson.