One thing - the city offices of Enterprise (as well as all other brands) are closed by 6 pm weekdays and are closed on Sundays. So if you arrive or depart outside the business hours, you need to have a plan.
Trip report: The Sky Train was almost as much fun as a roller coaster. I called Enterprise before we got on the train and they were there in less than five minutes when we arrived.. I gave the fellow $5. The service at Enterprise was courteous and they gave me upgrades and more discounts. I took the card they had for the cab company they use. On the return, our flight was at 6 am so I had to return the car before 6 pm of the previous day. We spent that night at the La Quinta- Arcadia, which is a five minute walk from Enterprise (there is no other reason to stay there). I used the cab recommended by Enterprise. It cost $10 to be driven to the airport at 4:30 am. Excellent all around experience and thanks again. The total cost for a week's rental of an intermediate car was $160, all in. The airport site was charging more than double that and you would have to ride in that bus that is for all companies and terminals.