I went last year with my wife to Universal 2 weekends after Labor Day, you'll be surprised how busy it still really is. Granted it will still be ALOT less busy than other times of the year. But on most of the main rides you'll still be waiting 45 min to an hour. But with that said the Harry Potter areas are some of the best themed areas of ANY park, I dare say its better than anything Disney has done, especially the new Diagon Alley area.