Felt Devox?

I would suggest that is a very good bar compared to spending 1000-1500$ on a new set up.

Others will chime in,

You're biggest gain is going to be not from material but from fit/comfort optimization and aerodynamic advantages. Just going from alloy to carbon isn't that big of a deal.

If you have the aluminum Bayonet 3 bars, then it is not much of a gain in performance. That said, I just upgraded my Felt aluminum bars to carbon aero bars. These are the chief advantages

• Carbon is likely more aero, because designers can achieve thinner, continuous, slipperier shapes with carbon than is possible with aluminum.
• Carbon is lighter, a lot lighter. I shaved 425 grams from my cockpit. Weight may matter less on TT bikes, but that is 0.9 lbs. eliminated.
• Better looking. Eye of the beholder, but better integration and smoother lines is pretty nice.
  

If your position is dialed in on the alloy bars then it may not be worth upgrading. If you can improve your fit with new bars then the upgrade would be justified. I like the Zipp Vuka (alloy or carbon) for adjustability.