The true power of the Sharingan is not to see the future, but to make it.
The true power of the Byakugan is to know everything in the present .
IMO there are better powers. I'd rather be a master of Shadow Imitation, for nothing else except the immense comedy value.
*walks through park*
*sees person you hate*
Kage Mane no jutsu!
*runs other person into trees even after they lose consciousness*
Before any pedants say that I would get hurt too, I won't, because I'm smart enough to release the technique just before he hits the tree.