I have a new KM/Regen I made to play through the new Praetoria content. He is at level 20 right now and so far the combination of stuns, knockdown, -DMG and yes, even knockback, work really well together. I know a lot of people don't like Repulsing Torrent but its knockback is perfect for giving you just a little bit of breathing room to heal up or click Reconstruction.