Universal Studios Orlando

Surfside is great for the price. I think it's only like 4 years old.

Portofino and Royal Pacific are very nice, but more expensive.

Hard Rock and Royal Pacific are worth the price imo since they are walking distance if you didn't want to wait for the boats and you get unlimited fast pass. Just be aware there are a couple of the big rides like Velocicoaster that does not have a fast pass entrance. Technically you can do both parks in two days, but they have deals now where you get a 3rd day free.

Also be aware that the attractions there are made for older kids and adults. Not a ton for younger kids.

One day, both parks with express pass is possible.

2 days without express pass, one park a day, will let you see a good portion of the parks if you get there early and prioritize the rides correctly.

I do both parks in a day without express on some trips to visit family and hit everything thing I think is a must do, but I know what I like and make sure to hit the new stuff first and skip the things I don't want to do.

If you want to take your time, 3 days would do it. Do one park each day and then spend the last day shopping and revisiting the stuff you enjoyed in each park. If you love Harry Potter, the shopping will take a significant amount of time.

Times could get thrown out the window if you want to do something stupid like go inbetween christmas and new years, basically the busiest week for theme parks all year.

Family lives there, so never stayed on site. Have wanted to stay in Portifino though.

2 is plenty.

I like the theming of their hotels over Disney. Especially Canana Bay is a fun 1960s motel.