I have used Fox rent a car her in Phoenix now on two separate occasions. If you are going for a bargain rental car, then that is what you are getting. The car selection is more limited and the "accommodations" are not a plush as others. But in my experience I have gotten in (although the wait line is normally longer than others), gotten my midget economy rental, gotten out, and gotten on with my trip.
Nothing special up or down. Adequate to a tee.