Does anyone have any experience with E-Z Rent-A-Car?
I searched Usenet without finding any opinions, pro
or con.

Short answer, no. I used Payless in Orlando once....perfect bait and
switch. They didn't have the car I had a confirmed reservation for. They
had other, higher cost, vehicles. I was under time restraints so I had to
take it. Had it been Hertz, I would have had a car at the original rate,
even if all they had was a Lincoln.

Alternatively, have you explored Priceline.com for a rental? I have used
them successfully more than once. They tend to use the biggies like Avis
and Hertz. If their program fits your plans, they are hard to beat. (for
hotel rooms, too)