Disney has an emotional draw that Universal doesn’t have. It’s every kid’s dream to go to Disney World.
The Disney bubble is hermetically sealed. Everyone stays in character all the time and you can’t see the real world from inside Disney World. (Mostly, actually.)
The non-tipped CMs are uniformly outstanding. I’ve never had a bad experience, including the ones who work the telephones. I’ve had a number of outstanding experiences. (The tipped staff are more hit and miss. I know I’ve banged this drum before, but some are complacent and some are too obviously just working for the tips, or even expect them to the point of not needing to make any effort at all.)
The Disney parades are better than the Universal ones. The fireworks are in a whole different category.
The thrill rides at Universal are better than the ones at Disney. The “mixed media” rides — Spider-Man, Kong — are mind-blowingly incredible. We have nothing like them in the UK, so far as I know. Disney has FOP, but that’s all they have in this league.
The theming at WWOHP, especially Diagon Alley, is exceptional. It’s better than anything at Disney.
The wider theming at Universal is patchy. USF is better than IOA. You can sometimes see the outside world. The team members (is that what they call them?) are not in the same class as the ones at WDW. They step out of character — unforgivably I was in Diagon Alley at close one night: I came out of the Leaky Cauldron and there was an almost aggressive line of security guards ushering people away. They were wearing modern dress. It totally ruined the magic. And Disney never tells you to leave like that.
I always thought I’d do both UOR and WDW every trip. At Christmas I only did WDW because it was a short trip (six nights) and it was Christmas and there was too much going on at WDW. But in general, UOR is a must-do for me.
I think it’s impossible to say one is better than the other. Each has strengths and weaknesses. But both are mostly incredible places to visit. Really wonderful.