I would vote for November nicer weather, less crowds, Disney World is in full Christmas mode. Being from Texas, the weather in September is the same in Florida and I would be miserable walking around outside all day 90+ degree's. My birthday is in September and I have always wanted to experience F&W but I cant bring my self to commit to September and October is not an option. Were went to Universal in June 2017 it was too hot for my taste and I needed a lot of breaks. November is our favorite time to visit, Thanksgiving week is a great time to visit, I have also been second week of November several times. Right after Thanksgiving is nice too.