Recently flew with both the A380 and the 789 with the unmentionable airline, AUH-MEL with the A380 and PER-AUH with the 789. Both times in a window business seat, which is the same installation on both airframes.
I have to say i do prefer the A380. It is far more quiet, and of course more spacious as well. The additional stowage space in the sidewall alone is huge and i didn't have to use the overhead lockers at all. Only thing the 789 has that i would want on other planes as well are those huge windows, that still allow a limited outside view, even if fully dimmed down.