I'm assuming from what you say that you've never been to US/IoA? I think you'll be pleasantly surprised if you choose to go. The whole USF franchise really does give Disney a run for its money. The attention to detail is equally as good and many of the attractions are truly incredible.
I would definitely not count myself as a thrill-ride fan, but some of my favourite rides are at USF. Spiderman is, arguably, the best theme park ride of all. The Mummy is superb and, even if you're not a coaster fan, I'd encourage you to give it a go. I was terrified before riding for the first time, but I was determined to do it and it's actually quite tame as coasters go. The theming and effects are amazing.
Shrek 4-D is, in my mind, the best show of its kind. Well, I suppose I'd have to say it shares the honours with Mickey's Philharmagic. There's nothing like Terminator 2 - incredible. Men in Black is great fun. At IoA, the theming is amazing. I particularly love the Lost Continent and it has two really good shows - The Eighth Voyage of Sindbad and Poseidon's Fury, plus the talking fountain (simply great entertainment).
The whole place is very compact - you enter via CityWalk which, in itself, is a great entertainment complex - with both parks next door to one another. You can easily do both parks in a day and just visit the headliner attractions if you choose to. For me, to visit Orlando and not do Universal is to miss out big time.