My top priorities are schedule, fare, upgradeability and the program I earn miles in. Their order varies from trip to trip, but they're ahead of anything else. The difference in comfort between one airplane and another, in the form they are put into operation as opposed to the form in which they are promoted when still on the drawing boards, is well down the list. (I might make an exception for a 787 versus an RJ, but versus another reasonably large and modern plane, nope.)