On the 787 you often have no choice. On an AA MAD-DFW flight on Thursday the shades were set to full dark shortly after takeoff and were reopened close to landing. You had no ability to lighten them yourself. I thought this was unnecessarily restrictive as I have always enjoyed looking out the window on long haul day flights.

Those planes are doubly irritating because (1) the windows don't go completely dark and if the sun is pointing at your window it can be very annoying, and (2) there is no way to open/lighten just a bottom portion of a window like you can with traditional shades.