I don't think it's dead, but there's definitely one foot in the grave.

At Hertz, I definitely don't feel valued as a loyal member. I'm sure there are many reasons, some of which include that Prez Circle is included if you are any of the higher tiers at United/Delta, which is tens of thousands of people (many who may have already had status, but some might not have). The threshold to earn status was much higher, but now it's been reduced to "only" 20 rentals. So I think that devalued some of the quality that was there.

A lot of people mention National, but I have had terrific experiences with Avis. Through my company I received President's Club status, which is not attainable through rentals alone, and while I don't get "thanked" for being President's Club, I do see benefits. Nearly always get double (or more) upgrades (Latest examples: Full-Size upgrade to BMW 528i) and my car is always right next to the booth, so I never have to walk anywhere to the car. It's not all puppies and ice cream cones, because their reward points is totally useless, whereas Hertz is pretty worth while.

For me, at the end of the day, it comes down to:

a) Do I want to drive a nice car, get decent treatment, have my car up front, and relatively no hassle, but earn little rewards

or

b) Do I want to drive a car that smells of smoke, it's higher mileage, base models, rare upgrades, walk to the last row in the garage but I can cash in for rewards every handful of rentals?

Yes, I was generalizing, but that's the overall gist. For me, it comes down to points, so I rent with Hertz when there's a special, and Avis when there isn't.