I've been using a Sawyer 90 from the US for the last couple of years.
Tapered oval carbon shaft is very flexy.
Handle is wood, that wears nicely and feels comfortable.
No idea on science of blade design stuff, but I had a lot of shoulder pain before I started using this.
And it's really pretty.
I wonder if I can find a photo....
There it is on the 12' PSH.....

Returning to using my previous paddle, it feels hugely stiff and wooden, unpleasant, unusable for even a short paddle.