I love Disneyland in California. I've been about 4-5 times and am planning to go again next year and take in southern California while I'm at it. It only takes a day or two to get around the park and go on all of the rides. We usually stay in a nearby hotel and walk there and walk home at the end of the day.
I haven't been to Disneyworld in Florida and it looks like it would need at least a week to get around it. Also, you can't walk to it from a hotel.