It all depends on the goals of your vacation, the ages and energy levels of the people in your party, the time you have available, the level of crowds at the parks.
As other have said here, if you like thrill rides, you'll find them at Universal/IOA. If you have younger kids who love Nickelodeon and Nicktoons characters or Spiderman you will make them happy by visiting Universal/IOA.
For my family we go occasionally during our trips to Orlando We always visit SeaWorld and spend as many days on Disney property as we can. We're going to US/IOA for two days on our trip this summer because we're going with a rabid 6 year old Spiderman addict! The kids will love some of the water rides/play areas , we'll visit parts of the parks each day and head back to our hotel to swim later in the day. And we'll definitely have at least one meal at Margaritaville, we love it.