Rudi ~ I'm an Avis Preferred member primarily, and I am Hertz Gold, though I have never used it.

For Avis the service is usually very fast in major airports. They drop you off at or near your car and you leave and that's it. It's not quite the same, and probably one small stop lower from Hertz. If the weather was bad, I'd probably prefer Hertz with the canopies, but personally I go for whoever is least expensive on personal trips, and I have to go with Avis on business trips.

I would just recommend giving Avis a try since it is free for you.