As I thought, the vector burning burns the lines and ignores the fills. This will be great if you want to burn outlines to paint in later, or are doing line-based designs. The stipple thing somebody was doing with a pen in another thread would be a good candidate. The vector burning was also very quick – less than 10 minutes for the 6-inch tall oval shown here. The vector code was generated with the inkscape plugin.
The other burn is an earlier version of the same plaque, round instead of oval, and 9 inches tall. It was burned with the raster style. As you can see, the raster style is more consistent overall and has great detail. It also took several hours to burn, so there are trade offs with each style. The raster was generated with LaserEtch.