With an express pass and good plan you could easily do the 12 of 15 of the best rides in both parks
We stayed at royal pacific 3 nights and two mornings out of 3 we did every ride we wanted in both parks before lunch.
Express pass is worth the money
I wouldn't want to do it without
Depends if it can be used when you are there though and depends on the numbers they are letting in
Also on nights like that maybe they don't operate the rides to full capacity?
With express pass Bear in mind we only do disney and universal once you decade and travel a long time to get the chance so we want to do it as well as we can
The must dos:
HP both lands and both trains (as they are different) and walking around there as there's load to look at
Jurrasic park cruise
Could do all of those in 4 hours with an express past