http://www.youtube.com/watch?v=G5_ZD6q2qeQ

i think it is but what about you

totally. its so easy to dodge/counter enemy's power attack which normally hurts.

edit: ah i thought it was slow mo perk in block;;

It's a good advantage to have but not essential

I only have the first point in it so far, but I find it really handy. Makes shooting moving targets heaps easier, and if you're having a bow war with somebody else you can dodge their arrows quite easily with it.