Ive been in real firefights. Iraq (Desert Storm, Iraqi Freedom), Herzegovina, Haiti. It gets hairy but you actually get more angry than scared. At least for me. Was deployed 3 times. Spent about 2 1/2 years of my life deployed. In all the times I was shot at I actually only got hit by someone in our own army (he creased my thigh). CS skills dont mean much with the shooting aspect, but there is definite merit for the tactical side like going thru buildings, securing areas, TEAMWORK, etc. As for the "Boom Headshot", The US military uses the 50 cal BMG rifle for snipers. When this thing hits people they actually burst. Heads, arms anything it hits. As for running faster with the knife in real combat, well dont bring a knife to a gun fight. As for what you folks would really do in that situation I wouldnt know. Some run some stand their ground. I assume most of you would stand your ground if you were in the military, or run as civilians becuz that would be the smart thing to do. I can tell you all that youll find that in that situation youll have more courage than you think.