apple tends to release updates around 5pm EST, when (i assume) they assume the east coast is headed home... so not everyone is downloading at that moment. i always find that late at night is best for DL speeds, but honestly... i update when i find out there's an update. we're talking 1.5 gigs, more or less, so it's not a massive DL. so, as chrfr above suggests, "download the update when it's convenient for you".