I have used Multi-Pass for years now, and it gives you great control over the entire scene - especially if certain systems such as mine do not like to render out pieces with more than two people and a simple background.  

 Generally, with larger scenes, I do a pass for the background, a pass for mid-ground, and a pass for foreground- added to all of the other uses this gives me greater control over the end product.

I also use it for specific lighting- a pass for specular, a pass for ambient and a diffuse, DOF, and Zdepth as well as a pass for shadows only on certain pieces such as scenes involving buildings, cars, ect.