We just did both parks in one day the Sunday before Thanksgiving. We were off-site this trip, and I was a little worried, but we had NO problems at all. We arrived very early, too early actually, so were there for rope drop. Went to US first and straight on Rip, Ride, Rocket. Then we did all the major attractions there (rides, not shows). Had lunch at Mels, and were at IOA shortly after. We rode all major rides (not Bluto's or Ripshaw) and were done well before dinner. I was amazed, but we never waited more than 20 minutes and less than that for most rides. All this was without the Express Pass.