There are some amazing off-site properties in the Orlando area that offer so many different choices. If you want to save a little, staying off site may be the answer. While odds are you will have to have a car and probably pay for parking, sometimes the savings can still be worth it. I have rented a three bedroom house with private pool less than 5 minutes from Disney for less than the cost of the Disney value resorts.
Every trip is different, there is not right or wrong answer. Some situations I would say definitely a better value to stay on property and others not.