All interesting. If I'm on a 737 or equivalent., I always try to book 1A or 1F. Little more space, easier to get to the head without bothering your seatmate. Usually say no to requests to swap unless a kid's involved. And call me old-fashioned but, when traveling with spouse or kids, I always try to buy seats side-by-side. If I cannot do that, I would never ask someone to swap seats.