Even though my Sunpak 383 was angled up I still got a reflection on the window, so I know I have to be more careful about reflections. This image was my most successful in looking "natural". The flash was set at ISO 100, "A" mode and 1/16th power. The camera settings reflect the shutter speed I determined was necessary to allow for detail through the windows. A slower shutter speed would make that view too dark...even black. I found that shutter speed by going into Aperture mode and watching the window content. I had to play with the aperture to get the amount of flash I needed. I was working in full manual on the camera.
A reminder for Sony 717 users: Make sure to enable the hot shoe if you're using an external flash without a cord. The Sony flash has a cord and the hot shoe doesn't have to be enabled.