I did give Disrupt a shot and it's pretty good. Not amazing, but pretty good. With an Acc, it can reliably stun 2 or 3 out of 5 +2 minions. Not all of them, but enough to warrant taking it. Every so often a Lt will stun, but I can't tell if it stacking with Precise Strike, or if it stacking with itself on a 2nd pulse? Not sure. Maybe the stun could be longer, but honestly, it works pretty good w/o extra slots.
One caveat I have noticed though: It has a very small aura. Mobs have to be in very close range melee. I really notice the difference between this and my Tanker.