I have two black CF clear-coated frames, one glossy and the other matte. IMO, they're equally durable but the gloss shows scuffing, scratches and dings more readily than matte. That said, the finish is pretty tough. I've ridden the glossy frame over 10K miles with a fair number on dirt roads with gravel/rocks and there's very little in the way of obvious dings under the down tube or anywhere else on the frame and no chips anywhere. And I don't handle it with kid gloves.
My wife's CF Madone, on the other hand, has a number of significant chips in its paint. It doesn't seem to adhere as well as the clearcoat on my bikes.
Ive seen a few posts of cosmetic issues with the matte finishes. If you do get a little scratch or scuff, you cant polish it out like you can on a gloss finish. If you do, the matte turns to gloss which is very noticeable. I dont own a matte finish bike, but just what I've seen posted a few times.