I've yet to find a truly stellar car rental agency at Sky Harbor. Started off badly. Despite only 3 people in line in front of me, I waited nearly 15 minutes. So, glacier-like pace is an appropriate descriptor. No problems at the counter. The staff was friendly and did not pressure me to purchase the unnecessary insurance. Back to negative when I arrived outside and there was no car to be seen. It had just been returned and was being washed. Another 15 minutes of waiting. Not cool. The positives were that Hertz's price was surprisingly the lowest, using a USAA discount, the car was clean and smelled great, and the return process was the best I've experienced. Bottom line: a mixed bag with plenty of room for improvement. Unfortunately, Hertz is big enough that they will not read this review and likely make no changes to improve service.