I guess. But i do wonder if there isn't some framework for thinking about the tradeoff in a quasi-objective way. Is it possible to make any kind of general statements about the marginal utility of improvements in weight/thickness and battery life?
One hour of battery life lets me take my laptop to a meeting, or sit on the sofa for a while. Two hours lets me watch a movie on the battery. Eight hours lets me work away from a power socket all day. Twelve hours lets me do that and read HN in the evening. Twenty-four hours is longer than i'm ever away from a power socket. It feels like there's steadily increasing utility up to that "as long as i want to be sat in front of a screen in one day" point.
A 15 inch, 2.41 cm thick, 2.54 kg laptop rests comfortably on my thighs, goes in a padded envelope, and fits in my satchel without taking up much space. A 15 inch, 2.79 cm thick, 2.5 kg laptop somehow did seem a lot more ungainly. A 15 inch, 1.55 cm thick, 1.83 kg laptop fits in a bag just as easily, and is comfortable to hold in one hand. Given that i don't often hold a laptop in one hand, that seems like a small increase in utility.
Are there other reasons why that 0.86 cm of thickness and 0.71 kg of weight are a real improvement? What does it let me do that i couldn't before?