The 777 feels narrower than say the 747 upper deck window seats, but that's because of the storage area near the window. Similarly the A380 upper deck window seats feel more spacious because there is storage space along the windows (iirc). But the actual seats themselves are identical, just that some extra space near the window makes them feel larger. Also, I think there is some variation of the laptop tray/drawer, with ones on the 777 being smaller than on the 747 iirc.