Carbon fiber offers the potential for a higher strength to weigh ratio than virtually any other material. This is at the heart of it's use in the pro peloton. If bike weight is your driving issue (can you feel the difference between carrying one versus two water bottles?), carbon fiber is the answer. Carbon fiber can also be formed into a number of shapes beyond round tubes. As such it can offer a very contemporary look that steel doesn't offer. Beyond this, carbon looks very special with just a clear coat finish, whether the fiber is a cosmetic woven fabric layer or a random scrim of fibers - nothing else looks like it.
For carbon tubing, I turn to Dedaccia or Maclean (who makes carbon fiber products for Reynolds). These are quality manufacturers in whom I have confidence. Money can be saved by purchasing from the far east, but I won't compromise my standards just to save money. So Dedaccia and Maclean are what I specify when I work with carbon fiber.
By combining different rear triangles and various tubes in the front triangle, I can tune the ride to meet my standards. To tune steering on a carbon fiber bike, I choose from among forks anufactured by Dedacciai, Easton, and True Temper. Between them I have a range of fork rakes available to address most needs.