I haven't tried the Fuze shaft (just Kielwood without CF interior), I do own the 12.4mm inFuze solid shaft (Kielwood with CF core) and compared to Predator 314 shaft and a bunch of CF shafts, it produced more CB deflection.
I doubt that the Fuze shaft is any better.
There is also the 10 pc. splice inFuze shaft that I haven't tried either but again, I doubt that there is a difference as the pie construction was never about deflection and more about providing radial consistency.
If you're looking for low deflection, I would look somewhere else (Predator.... wood or CF).
I don't feel that the inFuze produces more power than the 314 shaft, I don't think that it feels better, for me! It does looks pretty and really all I can say about Kielwood is that it looks pretty, for performance I prefer Predator wood and CF shafts or the JFlower SMO CF shaft.