With the loss of Magical Express it's an easy decision for me. Parking for
DVC resorts is free. The work rate I get for rentals is a wash compared to a service or Mears back and forth. I don't trust rideshare, especially in Orlando. I've had horrible experiences over the years and exclusively used Minnie Vans after that. The price of Minnie Vans has gone up significantly. A rental car provides so much freedom in the WDW bubble. You can dine at any resort and not wonder how you will get back. Disney Springs isn't a nightmare from the MK resort area. You can pickup groceries on your way to the resort, etc.
I would only use a company that allows you to skip the desk. I could never wait in those lines. Amex gives you automatic Hertz President's Circle and National Executive status on Platinum cards and it's easy to match with other companies.