From my short experience with CF shafts, it doesn't bring much improvement in performance compared to low-deflection wood shafts like the Predator shafts. It might just all be in our heads... If there is a difference, then it is so small that most players should and can compensate for it.
Its only real advantage is its durability, and if you are not a travelling pro player, then it's not that big of a deal.
The idea that you can just throw a cue in your car and leave it there with no worry is nice, but we are not there yet, as a wooden butt may warp as well, and the leather tip could get damaged as well. A full synthetic, high-quality cue is not out there yet.
As for low maintenance, I find the CF shaft picks up dirt faster and needs more cleaning during play (makes us spend money on wipes). It also pretty much requires wearing gloves (more money spent), which I can get used to but am really not a big fan of. Maybe if your pool hall is very highly maintained, it's different, but most are not.
I do believe that synthetic shafts (and butts and tips) are the future, and I am doing the switch myself now returning to the game, although it really out of curiosity.
I think that CF shafts should start to be an option or maybe the only option for custom cues as well, and cue design should take the black/grey shaft into consideration, although a full high-quality synthetic cue will put most cue makers out of business, as we won't need them for the playability or the fine craftsmanship; maybe they'll stick around as pieces of art for collectors only. I do appreciate a beautiful cue, but I don't see myself buying any custom cues ever again.