My only objection is when people recline their seat quickly. The person in front of me was, for lack of a better word, lurching back and forth during a flight last week. Every time, it made my iPad fall down (I'd been leaning it against the seat back).

Now, when the seat was reclined their seatback was inches from my face, which was annoying...but that's on Air France for cramming the rows that close together. I just leaned my seat back a little to compensate. Sucks to be the person in back whose seat doesn't recline...