There is a world of a difference in sound and feel between the two:
My basses with lots of steel reinforcement - the Gibson Victories, my Kramer XKB-10 Flying Broom, I believe also the Peavey T-40 - all sound a little thuddy. "Dead" is overstating it, but nothing jumps at you when you're playing it. They do as they're told, nothing more. A brutish sound, but not very lively. Perfect for locking in with the bass drum, laying a fundamental and not getting in the way of the guitars.
In contrast, my carbon neck Status Stealth II and the Parker Fly Bass have so much "sonic rebound" in their necks, all (literally all, and that does need some adjusting in your playing style) notes jump at you and sometimes also a little all over the place. Not very forgiving at all if you're a little rusty. I definitely agree with PROG-Tom that carbon necks resonate in an idiosyncratic way that feels unaccustomed at first.