Also remember that SEQ comes after two other factors for determining upgrades, so if you are on a flight that never has upgrades (ie Transcon) and you are not a Platinum on a Y/H fare, why bother rushing to check in at 24 hours. It really isn't going to change anything for you except to possibly let you book one of the blocked seats or the exit row, if the Platinums don't have all of them already.

S.