We're going in Sept. Have never been to Universal. My husband is not a roller coaster rider nor does he like motion rides like Body Wars in Epcot. Which would be the better park for us?
IOA is a fantastic park but if you aren't into thrill rides it's probably not the place for you. Going by what you have said I would say US. Back to the future is a motion ride but I can't think of anything else that wouldn't suit you at US.
If he likes movies I would say definitely Universal. We were at both just last week and while I loved the roller coasters at IOA we were more interested in the attractions at USO so we spent more time there (we are kidless and in our early 30's). At IOA we rode the coasters and water rides and were done. USO felt like money better spent (for us). HTH!
I've been to both parks several times and IoA is all about those thrill rides. So I would recommend Universal Studios. This park is mostly shows...and they are good! I recommend Horror Make-up Show & Terminator 3-D. Other shows are good like Ghostbusters, however it seems to draw teenage girls (yes...like me) more than anyone. Guys don't appreciate it much. "Rides" like Jaws and Twister are more like shows. Wild West Stunt Show and Blues Brothers are decent shows too, depending on your interests.
IoA has very, very few shows and those shows aren't very good. But for you, I believe you would get the most out of Universal.