I haven't tried the sport, but we recently started stocking them. I would imagine they are just as good, minus matching the crank perfectly. One tip I can give is if it works with your bike, flat black will probably look better over the long hall. My cages are shiny, but the inside of the downtube mounted cage already has a "custom" matte finish.

I trust the carbon cages more because of the way they make their cages (thin foam-like skeleton) allows them to actually crate structure with their carbon cages vs those other uberlightweight brand cages that are just one flat carbon curve. The plastic ones will probably be easier to pull bottles in and out of, as the carbon ones are really, really snug. But my brain keeps telling me that the plastic ones might get bent out of shape over time, even though that would take a lot of abuse.