I received my new Nikon SB-600 on Monday. I have not had a lot of time to play  with it, but from what I have seen, it eliminates harsh shadows and allows me to adjust the angle of light in a very flexible way. The LCD on the back is a little intimidating at first, as it uses symbols that are unfamiliar to most photographers who have never used a separate flash before, but it is easy enough to learn and the device will talk to an iTTL (intelligent Through The Lens) camera and immediately add proper lighting. There are still many features of the flash as well as the flash/camera combo that I have not yet explored.  I really like the built in flash diffuser, it forces the flash to a wide angle and makes light bounce around the subject and causes a soft shadow. The flash works well with faces, although, I am eager to try it with the more sensitive 35mm f/1.8 lens when it ships.