Well, MD, you are a better woman than me, with that speed on the Jamis. Of course, I do have a bag, a rack, and my lock in the bag. It feels like I am dragging a load on the rear, even on a flat. I can up to speeds of 16-18 on a flat, but I guess there's not a whole lot of flats around here.
I guess I have come to terms with the fact that I will be using this bike for "fun" rides around town and errands. I still love the way it looks.