Two simple mods to change your GTA IV experience for the better. I've only had this for personal use but someone requested me to put these up for you guys.

This will increase the damage from all guns, but it is still balanced.
Decreases the max amount of ammo to 5 clips( Glock max ammo = 17x5 = 85 ).
Shotguns are now actually effective at close range.
Physical force from all guns are reduced.
All weapon ranges are increased.

Explosives have not been edited.

Realistic amount of peds and police
This will about double the amount of peds and reduce the amount of patrolling police cars and patrolling police officers on the street. They're still there, but you will see them less often. They will still arrive in full numbers if they get a call from somebody or you get wanted.
Peds are doubled at night time aswell.

GTAForums topic:
http://www.gtaforums.com/index.php?act=ST&f=58&t=403363