If you're going to use scanline you're better off staying away from the skylight method, for the reasons Laurens brings up and because its really really slow. Instead use scanline and a custom light set up, like a light dome made up of spot lights. This script makes one easily and quickly and allows you to tweak the…
I don't mean to answer for Prophecies, but I bounce back and forth between the two methods, or I did until they fucked up the edge padding in mental ray... It really boils down to what you need. If you're trying to bake in a particular lighting effect like a top down light where the object is more shaded on the bottom than…
With some pieces mostly static environment art with very particular lighting, you might want a shadow cast from an object. It could be that its easier to bake in that shadow rather than try and do it with costly lighting effects. A good example is the shadow of a grate on a specific prop or section of wall/floor, or a…