One trip we stayed at three resorts, but one was at Universal. We first stayed about three nights at AKL, then about a week or so at Pop Century, then three or four nights at Royal Pacific. We drove to Florida, so we had the car. It also was November, so the weather was wonderful. The crowds, except for around Thanksgiving, were wonderful, too. I really enjoyed going to different resorts.
I must say that Universal has the notch up on Disney in the service department for their resort guests. The food is wonderful. The room was wonderful. The short trip to the parks is wonderful. The front of the line privilege is, well, so far beyond wonderful, that I cannot find the right words.
Getting back to the point, I love to switch resorts - it lets you try the more expensive ones for a few days. WDW moves your luggage for you, so going to three or more would be fun.