It has more missions a better storyline and much more.
Ill start of saying CoD 4 has alots more mission then CoD 5, and in cod 4 its a modern war, in cod 5 its world war 2...... again. We want to see new things. Also the internet part is alot better on CoD4. U have all sorts of choises that u dont have in CoD5.
In CoD5 there are about 12 missions or so. And a bonus. Nazi Zombiesm wich is great. the graphics havent improved at all. And the story is abit twisted.
CoD5 is thoug fun with banzai warriors who will suprise you. And grenades are lots more effective, then cod4.
call of duty4 vs call of duty 5... I think that call of duty 5 is better by a small amount..
Cod4's argument
.better storyline .more missions .better guns .better online play
Cod5's argument
.more fun to play .better graphics .no helicopters to hide from .outrageous killing .banzai attacks are funny when you stop them .more ai overall cod5 is the better game in MY view and many others but if you like cod4 better you still have better taste than many moh(medal of honor) fans so good on you.
Devil your arguments about the helicopters makes this more challenging. Although at the beginning you won't have a good enough score to be too worried about the chopper. Just don't use an LMG. Anyway, I havent really played COD5, but I like the weapons in COD4 better (i have played multiplayer), and the storyline in COD5 is not nearly as good as COD4s because you don't know how it ends. I won't spoil it for you here.