I wish I had better news, but from my experience (over 40 years of frequent traveling, both nationally and internationally) most of the car rental companies suck at one level or another. I rent a car every week and am not partial to any one rental company, I just try to stick to the major companies and use whoever I can get the most airline partner bonus points with. There's almost no value in any of the car rental company loyalty programs, at least not for me.

A major factor is location. There can be a lot of difference in the attitude, quality of the vehicles, and the service you get from one rental location to another, even with the same company.

I've been exclusively using Hertz for the past few months and, overall, I've found their cars to be not cleaned very well and quite often previously smoked in. Counter reps are mostly pleasant but I don't think any of them get bonus points for going out of their way to ensure your satisfaction as a customer. Hertz's recent price increases have begun to show up and they're not really all that attractive, so I'm going over to Alamo for a little while.

I'd use National but they're vastly overpriced. Enterprise has generally treated me well but they're also usually overpriced.

Good luck!