One shot one kill? Finally a semi-realistic FPS. Personally though, I think an awesomely realistic game should include individual hit boxes for each human appendage. It takes two to thee shots in the outer extremities to make you go down and one to two for the chest for you to go down. When you're down you have to call out for a medic or something. You bleed out fast if no one is helping you. Also, depending on the weapons caliber, it will change how many hits it requires for downing.
Also, this game is pretty cool in the fact you can guild your gun from the receiver up. Damn, that's pretty cool.