When I flew last week to/from FRA, the middle C cabin was full. It was loud and I got to experience the June rush of bladder-challenged folks to the lavs. I agree that it can get a little crazy in the galley, however it is usually during meals when you're awake anyway.
As far as the window seats, there is not much to see except darkness and water-especially to AMS-so that will not be an issue for me.
The privacy of rows 8/9 seem to be superior to those of ?-15 of the middle cabin.
BTW, does anyone know if the birds flying to/from IAD-AMS have the C+/power, or is it just a toss up?