ezcar rental/thrifty car rentals

[Lisa10]

So I don't have much experience renting cars, but need one for Aug 1- 10 trip to Orlando. On line I found what seems to be decent rates - about $270 for either Ezcar rentals or Thrifty. Anyone had experiences with these companies? I'm hesitating because they are not one of the big names (like Hertz) who rates were double. Also, do car rental companies want us to purchase insurance? I called my own personal car insurance agent and they said I would be covered anyway with my own policy I already have.