The walk from the Contemporary is very short and nice. You end up at the Main entrance to the Magic Kingdom, right where you would get off the monorail. That way, once you are on the boat from WL to Contemporary, the rest of the trip is at your own pace. I do remember sitting in a monorail at the Poly waiting for 25 minutes to move to the next stop.
If I were on a time schedule, I would like to have as much control of my fate as possible.