So when Spock yells Khaaaannn!!, is it really effective?
No. Funny, though.
It's so obviously borrowing on Shatner's much more effective yell. After all, Kirk had such a magnificent set of lungs, we heard him all the way through the crust of the Genesis planet and out into space, where sound can't travel due to space being a vacuum.
(And don't anybody come along and snarkily point out that Kirk was yelling into a communicator, 'k? I know that.)
Spock's death in TWOK was effective, because there was no guarantee that Leonard Nimoy would come back to the role. We really didn't know what would happen.
In this movie, it was painfully obvious that nuKirk wouldn't stay dead. It's like when most modern soap characters die - the audience knows it's probably not forever, or even for very long, as the writers will either retcon what happened or pull out some bizarre plot twist to make it unhappen. That's what this nuTrek movie did with nuKhan's blood.