Yes, the kids loved it. They are very into HP now. Our oldest has become a bit of a daredevil with rides. It also helps that they are both tall. The only ride my youngest is too short for is Hulk, and there was no way he was doing that.
There was plenty to do for 4 days. We spent the afternoon Tuesday eating and shopping in Diagon Alley and took the train to Hogsmeade. Wednesday was all IOA. Thursday we did Volcano Bay after rope dropping Hagrids. Friday, we rope dropped Velocicoaster (3 rides in 30 minutes) and then spent the day at Universal. Saturday we rope dropped Hagrids and Velocicoaster (35 minutes from turnstiles getting off Velocicoaster) before checking out. We will probably do a longer trip next time!