My family has only been to Universal once for the first round of Harry Potter. We will only be there for a day arriving early and staying late. My plan is to be there the Thursday after Labor Day which at Disney is usually a pretty quiet time. We will purchase the one day park hopper pass to be able to see all things Potter. Question is that week of Labor Day do we need to purchase an express pass? According to crowd level charts I've looked at Universal will be more crowded than Disney World but getting as much done as possible and all of Potter is important to my family. Any knowledge of crowds at the Universal Parks, popularity of Harry Potter during this week and tips and advice for navigating the 2 parks would be appreciated. Thanks for the help and advice.