I've rented cars here a few times. I have never had a problem getting a car and am usually in and out in a minimal amount of time. I have always had a reservation, but I was not always part of their club.
For what it is worth, I'd suggest joining their Club Gold. It doesn't cost anything and, if for no other reason, you can walk to your car and skip both the queue and upsell at the counter.
I have always been able to return my car in a reasonable amount of time -- at least on par with the other agencies and other airports. They usually scan my car's barcode, print a receipt and send me on my way.
As always, your mileage may vary...