I'd recommend posting this in the PvP section, as that's where your intended audience is.

http://forum.square-enix.com/ffxiv/forums/1019

That being said, this was a nerf that's made DRK objectively (no longer subjectively) better at CC than even PLD and widened the gap between the jobs along with the Cover nerf.

To answer your question, yes, the one second taken away does make a difference in the scope of securing kills.