I do think a new fork *could* make a difference, despite what the naysayers say. It's just expensive, and unfortunately how much of a difference is something it seems like no one has much personal experience with. I know a carbon fork made a noticeable difference on my bike, but I bought a whole new bike and one that was actually sized to me (though funny enough one with a smaller tire) and the ride is better, but who know how much of that is the fork and how much is different geometry, or fit, or something.

I also, unfortunately, don't know exactly which fork to recommend - I know the vibration dampening between different full carbon bikes was different (very different, varying between taught and jumpy to extremely vibration absorbing) so different carbon fiber forks may be different. I know Specialized makes some nice ones for their road bikes.