We are doing Universal for 2 days after our Glory trip. We will be there for the 4th of July so we are staying on the property and getting no wait lines for resort guest. We knew that Disney would be way to crowded for line waits.
Anyway, I find it cheaper doing it on your own not through Carnival. They had Orlando hotels alot more expensive then we got it.
We usually stay at the Swan/Dolphin and it is great location. Also if you have an Entertainment book they have 50% off depending on availablity.