It was probably one of the best campaigns I've played in a COD game so it'd definitely be worth buying just for that (though I recommend staying away from Veteran difficulty if you ever do pick it up, the AI gets grenade happy (and they're extremely accurate with those grenades) when you set it to this which makes the levels frustrating as hell to complete (it's the main reason I never actually beat it on Veteran difficulty back in the day). The "All Ghillied Up" level still remains one of my all time favorite levels in an FPS game to date.