There are definitely two versions. You can usually tell pretty easily by the retail price. I'm not sure if you can get the carbon with kevlar/carbon weave with ti or other metal rails.
Mine is carbon railed and has the carbon shell with weave. I know they still make a nylon shelled version with the carbon rails, too.
From what I've read the carbon cx w/ weave version is slightly shorter in the nose, clearly has less padding than the standard arione, and shows it in the weight. Mine weighs 153 grams. I'm not totally sold on it, preferring the aliante more, but will try it some more before ditching it.