It is possible to get some very dramatic lighting with earlier or later lighting, but it is difficult for the casual photographer. The September pic is a good example. However, more often than not most people are not able to generate such a sharp image at such a time of day. The June image is an excellent example of the proper amount of natural light. (also these guidelines don't apply where artificial light is present, or an effect is being achieved, aka the cover)
The main problem with using un-natural light is the need for image correction. A good example of this is 1314 pic in the parking garage. I actually edited this picture for proper color.... I don't know if you have the origonal image available 1314, but here is the corrected version: http://img.villagephotos.com/p/2003-7/300749/24editcom.jpg
Lata! 
