Rayleigh flat out says he hit Kid and Laws crew with the blast and they took with only Law's weakest member feeling dizzy. http://read.mangashare.com/One-Piece...4/page012.html
Obviously the intensity can be controlled but if Luffy can even stun 3 Admirals at once with an undodgable AOE at this point then they might as well wrap it all up. That would mean Shanks or Hancock could wipe out the entire Marine force up to Admiral by themselves.