I don't know what the sunlight in early autumn looks in other parts of the U.S. or in other countries, but here in Philadelphia it's gorgeous, at least for the time-being. The humidity of summer has dropped, which clears the air and allows the normal crispness of direct sunlight to enhance textures and enhance contrast. Because the sun is lower in the sky, shadows are bolder and there are more opportunities for dramatic backlighting. Earlier sunsets allow you to take twilight and evening shots without having to wait until after 8:00 p.m.
I imagine that one could see a difference in the light even in chronically overcast climes. Those of you who who have first-hand experience should feel free enlighten me (pun intended). In the meantime, here are some examples of what I'm talking about. Perhaps they will inspire you to venture out into the autumn sunlight and get some memorable shots of your own.