On the performance side of things, the top CF shaft do create less deflection than top LD wood shafts.
Does it matters? yes! it will make any player at ant level more consistent, pro players understand this and this why the majority of them have adopted LD shaft in the last 30 years. And keep that sponsorship crap to yourself, even before CF, a lot of pro players sponsored by various cue makers had predator shafts on their cues, some of them removed the cat logo, some didn't bother...
I used to photograph pro pool, I got enough pictures of players with sponsor patches of one cue and a predator logo on the shaft to prove it.
I won't go into the added power debate, but really this is even easier to test than deflection...
So what else is there other than durability?
As if it's not enough for the traveling pro, add consistency. the shaft will play the same regardless of weather conditions. And that consistency is also between other shafts of the same makers (not the cheap crappy ones), so your backup shaft will play the same as the main shaft, less learning curve right on the spot if for some reason you need to switch shaft in the middle of a tournament.