Let me just say this, and I'm inviting a WORLD of poo on myself here but here goes.
OC spray, I've been hit with it to get certified for an armed security job which I ended up not taking. It SUCKS and is almost immediately debilitating. I'm no chump and it brought me to my knees for about 15 minutes. I'd honestly rather be shot or tazed or beaten or blown up, OC is the most miserable experience I can imagine next to having your fingernails ripped out. If you know how to use it right it's 99.999 percent effective. Then again if you're dealing with an individual armed with a gun it's usually better to bring your own. You can never have too many tools at your disposal though.
Sgt. of Marines, 5th Award Expert Rifle, 237/250
1st Award Expert Pistol, 382/400
D Co, 4th CEB, Engineers UP!! OEF 21JUN-20SEP2011