Weight plays a very important factor. I recently came accross an article about Chinese airlines where they have had to increase the "estimated" weight of pax due to the increase of obesity in that country. I wish I could find the article, it was really interesting. Although we don't acually weigh pax, weight and balance is estimated on the amount of pax we carry. The odd larger person certainly wont make a difference but with many airlines you do now pay for space. Premium economy is an example, although the service may be the same, you pay for the luxury of the extra room without having to pay the price of a business class fare. But saying that the seats are the same just more leg room so that doesn't resolve the arm rest issue. This is a tricky one, and one I have never come accross. All of the larger pax I have dealt with have just accepted the fact or they have booked Business class. I can see cases of discrimination happening. I remember a guy who complained because although his life jacket was under the seat he could not reach it due to his size, he phyisically could not reach it. Where do we draw the line? Obviously without trying to discriminate we are going to have to adopt a policy for these people. Does any airline have one?