Not since the invention of the leopard-print Snuggie had I ever had such a comfortable experience with a product and/or service. For a large corporation they are very personable and will do almost anything to help you with your rental experience whether it's an unexpected upgrade or downgrade or last-minute changes in your schedule. The Kia Optima I rented was spotless with a full tank and ran like a brand new car off the lot. It also changed my opinion on Kia's being the Korean version of a Pinto.
Keep your eyes on rates at different locations well before your trip. They tend to fluctuate quite a bit depending on demand and also note the fees and taxes because they do add up.
The Skyharbor car rental garage is also one of the most organized airport facilities I've ever been to. I'm from NY so my expectations on things like this are shattered and beaten up on a regular basis. :*(