I have not yet tried Duckfat although my wife has. We both work in town but usually work-out at lunch.I was up that way a couple of months ago. Dimillos's is a decent Restruant, but you should try Duckfat (Middle and India st.) for lunch sometime.
As for great portland restuarants, we love the Grill Room and the Corner Room. They have great food and are owned by a fellow sailor and dog lover. They also own the Front Room which we have yet to try.