I think if you test ride a carbon framed bike back to back with an Alu framed version there’s no doubt that you will go carbon, I bobbed some RF SIXC bars on my steed about 2 years ago and the benefits were instant, although riding a pair of Fox 36 VAN RC2’s the carbon bars to the buzz out of the trail.
I’ve ridden higher end Santa Cruz back to back and the carbon versions just sit up to pedal input, as others have said they are snappier and respond well,
I’m still of the opinion though that Carbon is for the elite, like in F1 cars it’s fine for Lewis Hamilton because he doesent pick up the repair bill.
Like Contadores spesh, it won’t be comming out of his pocket because it got mangled on the roof rack.
If it’s your 9 till 5 profession then there’s a benefit to having carbon, but they aren’t used for 2 to 5 years in the hands of a pro they probably do that many weeks in fact days ?