Carbon fiber is stiff, which translates into more brittle than fiberglass. It is cut (using a dremel) and finished the same as glass. It's black so you can't see through it. Once you build a plane with it, you will think all fiberglass planes are wimpy because they squish (notice I said "all fiberglass" and not fiberglass laminates).
A common fiberglass fuse failure is the tail whip that occurs on a hard landing. This results in a "greenstick" fracture right behind the wing if you are lucky. This is less likely to happen with carbon fiber because it will not whip around. It will be stiff and strong (much stronger than fiberglass) and then it will break. No carbon fiber plane of ours has ever failed for any reasonable stress. In fact, one of ours had a run in with a 40% Extra and flew through it and landed. The Extra, with its stringers and monocote, was not resistant to the guided missile that hit it.
On the other hand, Gray and I (Lance) midaired with EACH OTHER in December with two carbon fiber planes. Little black tostada chips. But that's another story.
There is a common concern regarding carbon fiber and radio interference. It is claimed that carbon fiber will shield your antenna. However, from my experience with Electromagnetic interference shielding (EMI) and former life in electronics I know its not that simple.
Radio waves get blocked by absorption and reflection. Absorption happens when the signal is attenuated (reduced) by being diffused. This happens to your FM radio when driving into a tunnel. This is NOT what happens with our super thin walled fuselages. The other way is through reflection. To reflect a radio wave you need a conductor. Holes in the conductor (like the holes in our cloth weave) allow some frequencies of radio to pass and block others. CF is a conductor (fiberglass is not), but the thickness of the CF and the size of the aperatures have to be studied to determine if either is sufficient to decrease a signal in the 72MHz band.
Gray asked the radome designers at Raytheon. These guys should absolutely know, or get booted off their government contracts. They say we should experience no problems. However, Gray did have a radio glitch once in his CF Escape that appeared to be "fixed" by running the antenna outside.
I've never had a problem running the antenna outside the fuse and I've never tried running it inside.
It all comes down to trade offs. Right now we can get much stiffer fuselages using carbon fiber. Even Stiffer yet with carbon fiber and other sandwich materials. This gives the best flight characteristics. If we can achieve adequate stiffness and lightness using other materials we would switch (if they are also cheaper). I don't even know if the precaution of running the antenna outside is needed, but it is a small price to pay. I run mine down the bottom and no one seems to even notice until I'm cleaning my plane and it is upside down in its cradle.