Let me help you with this..
Just went to both parks yesterday. I had only been to Islands of Adventure before. First off, Universal Studios is a much better park than Islands of Adventure. Islands of Adventure is a true half day park. We were done with everything by around 11:00 am. Most of my gripes are with Islands of Adventure. But there were several things that I saw that needed work:
I'll give you that IOA is more of a half-day park, and Universal Studios Florida is a better all-around experience.
I walk through Disney and Universal parks on a weekly basis, and Suess Landing has seen a lot of improvement in the last year or so. Many surfaces have been repainted around the time of Grinchmas last year. That island is looking as good as when they built High in the Sky Suess Trolley Train Ride.
2. Jurassic Park: This sections was clearly mishandled. I don't get it. So many areas of opportunity here.
One of the best-balanced areas in the park, and a lot more cohesive than Dinoland USA.
3. Whatever the toon area is called in Islands of Adventure: I didn't ride a single ride in the section. Very unoriginal attractions and characters that I just don't care about. They need to pick better franchise to invest in and revamp this area.
Water rides anchor this area, so this area is more popular in the Summer time. IOA is smart to put all three water rides next to each other, although it doesn't help when it's colder or no one wants to ride them.
4. Marvel Island: This area felt like Six Flags. Little to no theming. It doesn't feel like you are entering marvel world. Really bad theming.
Marvel Super Hero Island is the Tomorrowland of the park, and has some amazing rides and atmosphere. It's a shame you didn't catch the villains/superheroes streetmosphere show, since that goes a long way toward pulling you into that world.
5. Islands of Adventure' Islands: Harry Potter feels out of place. What Potter does is transport you TO the Wizarding World. It feels like you are walking in the world. All the other sections fail to do that. I think all the other islands need to be redesigned to match what Potter has to offer.
Potter is nice, but I can't imagine it fitting in any better at any one of the Disney parks.
6. Better cleaning crew: While at Universal Studios monday, it wasn't very clean. There were still remains of Saturday's Mardi Gras celebration of the ground. It looked like it hadn't been swept at all. And this is 2 days later.
That's probably due to the confetti cannons. Park Services isn't a miracle worker, and Disney is known for pressure-washing everything... but I've seen plenty of dirty park areas at Disney parks. Especially the queue lines.
7.) Utilize the classic Hollywood Monsters: I feel like the Horror genera is underrepresented. A dark ride based on all the classic movie monsters would be perfect.
There's Graveyard, Horror Make-Up (hopefully you got a chance to see that, as that's a true classic), and the Monsters Cafe. Mummy kinda straddles that line, too (classic monster with a modern movie tie-in).
8.) Twister: Remove the ties to the film and just theme it around a disaster film.
Disaster Studios' Frank Kincaid might have something to say about that. After all, I'd take Twister over the old Narnia hack-job that ran for years at DHS.
9.) Universal's Kiddie area: Give it more TLC. Build a better facade for E.T. and refub the ride. It needs it. The movie posters outside the ride are over 10 years old now. No excuse for that. Get rid of Barney. Add something of substance.
No complaints here.
10.) Dinning: More Table service options
Two table service options in both parks (Confiscos/Mythos/Finnegans/Lombards), plus all of CityWalk? That's more than enough. That resort is worth a two-day visit at least, so you have more than enough options.
11.) Mummy: needs HD badly...
I'd settle for a better ending.
12.) Beetlejuice's Graveyard Review: It feels like it's in the wrong place...you know, in the middle of a New York street. And where was the Graveyard?
First off, it's location is in San Fransisco. Second, the stage is a castle/graveyard set. It's a little out of place, true, but now you're nit-picking.
13.) Meet and Greet: Need to have a bigger budget. They Meet and Greets feel so cheap and side-of-the-road.
Disney is the only place that places such an emphasis on meet-and-greets.