I requested AM which is not guaranteed but if i asked for PM i would get it my reasoning for requesting AM is mostly because DD will be in AM preschool and if they go at the same time they will have more time together, I will have some time to myself, less time running around and more time to do things with the kids if they both get out at 11:30 (different schools).
But I am second guessing. If DS gets PM I would have time each day one on one with the kids, my last year for that possibility. And I can sign DS up for art one day a week in the morning. And DS likes to sleep in until 7:30-8:30 so I would not have to wake him for school. The down side is I get no time to myself or afternoons to do things with the kids together and DS would have to come with me to drop DD at school or stay home with DH (when DH is not traveling) and that might be hard on DD, and DS would see his sister go to his old school with his old teachers and some of his friends (Montessori school so DD will be with some Kindergarters). I think DS would be fine learning in the afternoon and that class is usually smaller.