I found a terrific mod for the game that really makes it a bit more fun:
http://www.sheriffsdpt.com/main.html
Go to downloads, get the SSF realism mod. The guns aim a little bit tighter, and zero in faster, plus you get access to the enemy weapons (silenced uzi, ak-47). You can also carry primary weapons as secondary weapons, and vice versa (ie, you can have a beanbag shotty and an mp5). I read through the list of changes, and I thought they all sounded great, so I put on the mod. As simple realism mods go, this one gets a 9/10.