My family and I used a shuttle service to get from PC to WDW before. There was one experience that wasn't pretty. First of all, we were promised a van. They came late and instead of a van, they brought a smaller car and tried telling us that six people, nearly two dozen pieces of luggage, and a car seat for the guy's next group would all fit.
Uh no, it wouldn't. It was that bad that my parents had to get on the phone with the company and yell at them.
My family and I have also rented a car, walked to the port, or taken DME in the past