Dialyn nailed it. The manual tells you what the dials and buttons do, but not why you might want to use/not use or increase/decrease them. I'm very happy with the results I've gotten from the above settings, but if I can make better renders, why not? :O) And perhaps Niles or someone else could explain what the production render quality button does differently than the draft quality button? All the real options seem to be down below.