I have to go with painkiller. You can get away from the commando lunge once you know what to look for.
Painkiller is ridiculous, however if you're looking at a reality standpoint both have a basis in fact. A lot of military units, and particularly rebel and/or insurgent squads use drugs to keep themselves standing, which makes a case for painkiller. As a CPL holder, (that's concealed pistol license) I can tell you, any combat firearms instructor will tell you inside 15 feet both holstered the guy with the knife beats the pistol holder 80% of the time. Keeping in mind you don't have hip fire crosshairs in real life, and the need for exaggeration in video games for entertainment, neither are too far off.
You can't run and accurately hip fire anything other than a shotgun, and less than 1% of the population can accurately hip fire a pistol from a standing position at more than a few feet. Even less could no or quick scope a sniper rifle.
I shoot farely well in real life, I've even placed in some local competitions. If I could pull half the shit off I do in this game, (jumping off a building and getting a headshot before hitting the ground) I could quit work and shoot for a living.
All that being said, it's a damn video game everything in it is utter bullshit.