Here's what I would tell you.
The only research needed is to know which rides are the "headliners" and the ones you can't miss and which rides can be skipped.
Universal Studios side is movie-ride related like Disney's Hollywood Studios (or whatever they call it now)
Islands of Adventures is themed lands, like most of the Disney parks.
Islands of Adventure is circular like Epcot so pick a direction and go! And does theming as well, if not better, than Disney.
The childhood love (of Disney) is not there, but the technology knocks the socks off of anything Disney does.
I have been twice, going the third time next week. Haven't seen Harry Potter yet so that is a priority this time but still want to re-experience the things I loved in the past - Spiderman,Hulk, Jurassic Park, Suess Landing ("I could live here" - my wife who hates amusement parks said), Men in Black, Shrek, it's all so good.
IF you've got two full days, three at best, you will see it all and get to redo your favorites. With Harry Potter thrown in, I can't say yet how much more time that will take. I've heard the detail can consume your day. But if you're not a Potter-file, how long can you go on absorbing detail?
But I've read up on it (unofficial guides) and in the end, you can do it all with your circumstances and you will come away as a believer. It doesn't replace Disney (nothing can) but it is different than Disney and a wholly worthwhile different. Enjoy, and relax.
Oh. One more thing. Dining is not to the Disney level. Eat what you want, when you want. Mythos, or counter service, food is not the focus of US or IOA. Except maybe in Potterland and even that's not supposed to be outstanding. It's kind of refreshing to have the focus back on the attractions and not feel like you are missing something if you don't get the perfect reservations at the latest perfect restaurant like at Disney. (This is from someone who had has Cinderella's Castle reservations more than once for previous Disney trips! and every restuarant picked by ratings and hearsay to make sure we got all the best experiences.)
This trip to Orlando (next week) is a Discovery Cove/Universal trip without setting foot on Disney property!