Howdy,
Just wanted to throw my two cents in, for what it's worth.
1. Last year I traveled very little (I think 5 trips total).
2. For the 5 years prior to last year (01-05) I traveled a lot, 50+ trips each year.
3. I booked Avis mostly, occasionally National. Both gave me upgrades most of the time; the car check-out process was simple. No problem.
This year I'm traveling again (looks to be even more than before). I choose Hertz.
Why? I like to travel with my family (personal travel/vacations). I get free hotel rooms, free airfare - but I always ended up paying for a car.
The real straw was when Avis wrote me and sent me 2 "companion upgrade certificates". I needed these like I needed a whole in my head. So this year I started to look around - Hertz with the ZE1 thing will give me a free car. So I'm giving Hertz a whirl.
To me Hertz with the free car (and prestige collection at that) beats Avis preferred select hands down.
I'll let ya'll know how it works out.
Keep the faith,
Pakse