Weather wise I would prefer November. Unless you really like hot, humid, afternoon thundershower weather.
As far as Halloween decorations, only MK does Halloween. I am not sure when in September they go up. I know they were there the last week of September this year. The Christmas decorations will be going up through November, especially at the resorts. MK usually does the Halloween to Christmas switch right after Halloween.
November will be busier than September though these days it seems like the crowds don't go as low as they used to.
Whenever you decide to go I wish you a magical trip.
As far as Halloween decorations, only MK does Halloween. I am not sure when in September they go up. I know they were there the last week of September this year. The Christmas decorations will be going up through November, especially at the resorts. MK usually does the Halloween to Christmas switch right after Halloween.
November will be busier than September though these days it seems like the crowds don't go as low as they used to.
Whenever you decide to go I wish you a magical trip.