I've got both games, and I honestly think COD4 is to cartoonish...
... And the fact that 'You almost got killed. Your weezing like an old gas bag with a walking cain and no left leg, But! Wait three seconds and you'll be back to full health!'
Honestly.... You could run round pwning every1 and almost die each and every time and then go run away with your tail between you legs and then run back into the fight fit as a fiddle and repeat. So unrealistic.
Still a fun game though. Campain is good all those rebels running at you with RPG-7's