It's a red eye so everyone is going to be sleeping to some extent. I sleep about the same either at the window or not. For a 12 hour red eye flight I may get 4 hours sleep tops...usually broken up in hour segments. Even the time I flew Royal Laurel I probably only got four hours sleep tops.

I do pretty well with my trusty Bucky. The thing about Window for me is it seems to really put a strain on my neck leaning up against it like that. Though I haven't tried it in Premium Economy...just regular Economy.