Well, the game is "realistic" as much as gore is concerned. However, there are a lot things which are not realistic. M4 for instance, you should have the opportunity to fire the m4 without having to reload a nade. Also, reloading a nade takes more time than in real life than in the game. Final thing about M4 nades: in real life they do FAR more damage (take a look at Ghost Recon, that game does a good job at realism as much as weapons are concerned).
Enemy detection is not very realistic either. You can easily be spotted while crouching through the bushes, while in real life, you could stay in the bushes without being detected.
Another thing is the jumping part. If someone came up running towards you with whatever weapen he has, you wouldn't go jumping around in real life, while it proves pretty usefull in sof2.
And ofcourse the way damage is calculated in sof2 is not very realistic either. One shot with an AK in the head at full health, DOESN'T KILL! This is bullocks of course. A bullet in the head from a friggin' air-rifle can kill.
Final thing (before I go to bed): if you get shot in real life, you won't be able to instantly shoot back. You'll be a bit disorientated (to say the least) and need time to figure what is happening. The enemy would have time enough to shoot again, before you are able to shoot back.... not in sof2 though.
I am not complaining about the game, for I really like it, but it is a bit far fetched to call it "realistic".

Jonasdriessen->
*agreed* deaths in SOF2 are pretty unrealistic and sometimes funny,I cant keep myself from grinning when iIsee two guys dying the same way ..simultaniously.
Or the office ladies at the shop...they keep on typing even after you shoot their PC or them.
Fleeing enemies are a laugh too...they look soooo #### funny...with a serious face...hands at their heads,walking faster than a man running .
I don't want to talk about puking guys,ok a bullet in the stomach got to hurt...but twitching like that...is overdoing it.

Another thing....which really annoys me...
Enemies in open field with houses like in RMG missions...assault you altogether...they storm you no matter what...
After getting rid of those guys...only ppl in houses are left..who are easily whipped up
AI is NOT smart..really not...only sneaky

And it seems like every entity is 'locked' after it dies,or at least events handling is set to loooooooooow level.

Fire a bullet into a living guy...and the exit wound generates a splat on the wall , blown off limbs spurt blood....

do those things with a dead ent...no blood spurts...no exit wound splats.
Grenades dont blow living ents to bits...but dead or stunned ents...so it seems...

Ahhh there is so much I would change...its so much I would prefer telling it via telepathy...too lazy to type everything...