We usually move a couple of times.
The main reason is to change vantage points from which to experience the parks. We love AKL but feel too removed from the MK or Epcot to stay there the whole time (not to mention watching the fireworks, dining easily at many of our favorite restaurats or water transportation). So we usually go there first and enjoy this fantastic resort for a few days while solely going to Animal Kingdom and enjoying AKL's restaurants and experiences.
Then after three, four days I start missing the bustle of the Epcot area so we usually move over to the Boardwalk, Beach club or the Swan/ Dolphin (the Boardwalk is my favorite, the Beach club my son's favorite due to the pirate slide). I would never want to miss that relaxing walk back from Illuminations to my resort, after dark. (I've tried it the other way--on the buses with loads of people, no comparison). We go to Epcot and MGM for a couple days and then have Disney move us to a monorail resort.
Then we love to finish our stay at the GF (usually) and go to MK really early each morning and enjoy the electrical light parade, the lovely grounds, the motor launches (which I LOVE at night), the comfortable beds, fireworks and the restaurants at the other nearby resorts. It's a perfect ending for our vacation.