The truth is, there is really only one new ride in Harry Potter World, which itself is only one of the “Islands of Adventure”. That ride has been fully wrung out by now. That’s the Fly With Harry Potter ride. The coaster is Dueling Dragons which has been running since the park opened in 1999 and the junior coaster is the Flying Unicorn which opened in 2000.
The rest of the park has been open since 1999 and features Marvel Super Hero Island with the Hulk coaster, Dr. Doom’s Fearfall (a launch tower), and one of the greatest rides in the world, Spiderman. In Toon Island you’ll find a log flume ride that blows away Spalsh Mountain in all aspects except for the Song of the South dark ride section and Bluto’s river barges, which blows away Kali River Rapids. In Jurassic Park, there is a kids’ coaster, a kids’ play area, and the Jurassic Park raft ride that does rival Splash in every measure, except ride time. Finally there’s Suess Landing, ever want to walk through a Dr. Suess story? This is possibly much better than Toon Town and there are certainly more rides. You are definitely looking at a full day park here and should probably go mid week so you won’t have the weekend crowds to deal with. Wait times on all of the signature attractions can be every bit as bad as WDW.
Balance that against a night in the MK. And just to throw you a curve ball, Universal hosts its annual Halloween Horror Nights every year as well, but it isn’t for young kids and crowds can be really bad.