As a business traveler who is in and out of many airports and car rental facilities I can say that maybe I do travel way too much, but I do enjoy it. Having always used AVIS I am a long time Preferred member and have never had the problems I read about in many reviews on Yelp. Lucky so far I guess.
I must have had a total opposite experience from most everyone here recently. We arrived late last night and at about 11PM I walked up and saw my name on the board listing the spot my car was in. As I wanted to add a GPS system to my rental I was told to do that at the Preferred office down in the garage where my car was. The guy behind the counter there was friendly and helpful. Got my GPS and he amended my rental contract quickly. We were in and out of there in just a few minutes.
The only negative about this rental facility which is the main one for the airport is that it is about a 20 minute ride by shuttle bus so you do need to plan accordingly if pressed for time. Otherwise, facility itself is clean and well lit and houses pretty much all the main car rental companies.