I would like to know if the knockdown from the rank 2 of sniper triggers with enough frequency to be worth using. I wouldn't want it for a true sniper as enemies fall behind cover, but knocking down enemies when pelting them in the heat of combat could be handy. Makes me thing of the "and stay back" shotgun perk in new vegas.
So, does it happen often enough to be useful. Also consider that I will be using semi auto combat and assault rifles so I will be putting multiple hits into targets quickly.