jackal expresses my thoughts exactly - about the first organization (Which I have never heard of) and the Orlando Magicard discount which I use, even though I live here.
I live 35-45 minutes away and sometimes use two, one-day rentals at Thrifty when traveling for leisure. I have found that a 1-day rental before and another at the conclusion of my trip is a lot cheaper than paying for 3 weeks or more of airport or even off-airport parking. In addition, I get to leave my own car in my garage at home, protected from the elements. The Magicard discount make this work for me.