toby,
In my opinion, it is better to draw from above the target and let your bow come down during the draw. You have more muscles below the level of the bow (and gravity) to bring it down rather than just your upper deltoids to lift it.
The important thing to remember, no matter how you do it, is to maintain or attain an angle of 90 degrees between your bow arm and spine. Draw so you are "square" and level on the horizon THEN adjust your aim ( up or down as required) by moving your entire arm/shoulders power unit into alignment for the shot WHILE maintaining that critical 90* angle!
Arne