We did CL at Royal Pacific last Easter. It was good, not as good as Disney CL, but cheaper so a good deal. Main difference is you only have access checkin to checkout, NOT before and after on those days like Disney.
If you want to ride the Hogwarts Express ride between the two Harry Potter sections, you need the park to park ticket.
If you’re going at an even remotely busy time, stay at one of the Deluxe (Premier?) resorts so you can get the free Express Passes. You will hate going back to the FP system when you get back to Disney, the EP’s are so useful and easy to use. Just walk into the EP line at whichever ride you want to ride, at whatever time you want to ride it. The goal is a 20min or less wait for each ride, even at busy times.
If you are a water park family, do Volcano Bay. The not-so-lazy river there is now our favourite water park ride anywhere. And they use a MagicBand & FP style system for the lines on the bigger rides, plus there’s early entry for deluxe hotel guests. We loved VB more than the actual parks.
If you need a guide website, try
https://orlandoinformer.com/universal/ - we found it very detailed and a huge help.