This. The new 4 sec root is far far superior to the old knockback for pillar kiting etc and almost every other situation.
I wasn't keen about it on paper; but having it on a short cool down and not adding to or being affected by resolve comes in handy. I just gave it a good, honest try last night and it was effective. I just use my regular knockback when I myself am rooted, like from a leap, but if I can keep moving with the help of cure I use the root. Particularly when I am focusing on an objective; I then do not waste much time to engage the melee in my face more than to root them and keep moving to where I need/want to be.