OK, this is an example of having the pixel sampling set at 12 and the image rendered to a new window at twice the size of the final. It was reduced in PS with a little croppping off the top. The render time on this ended up being around 5 hours with most of the time spent rendering the bottom quarter. With the max pixel sampling and reduction of any left-over grain by resizing, FireFly can give a reasonably simulation of DOF.

@shadownet - Thanks for the info on the camera settings. I'll try them out later today. Oh, and keep your head down! :)