I agree with James and Bob.
I'll add that in my (limited) experience carbon has a different feel to it. I've drawn at least one bow with carbon limbs (no glass) that felt a good 10# heavier than it actually was (or at least what it was marked), and I wasn't alone in my opinion on that particular bow.
On the flip side, I shot one just this past weekend that was all carbon that was very sweet, but I knew when I drew it it had carbon limbs. No stack, very smooth, just felt a little heavier to me.
I've had several folks ask about getting carbon limbs in a Chek-Mate bow. Like James said, what's the point in adding to the cost and wait when you have a super product and can't build them fast enough already? Plus, in their testing, they just don't feel the customer is getting what they pay for with carbon, at least in their bows.
I'm not knocking carbon limbs or those that like them. Honestly I was a bit biased until I shot that bow this weekend. It has me re-thinking carbon limbs, at least in some bows--but I don't see me trading off my Crusader any time soon either.
Chad