5* is definitely better than not having 5*. Sometimes it's done nothing for me, other times it's taken me from Mid-Size to Prestige.

You have to manage your expectations. In my experience you can often get an upgrade, but definitely can't rely on it.

I made two reservations as Gold and status matched to 5*. Both reservations showed first time Gold and told me to go pick from the Gold section, but I went to 5* anyway as I had the status.

MSP had ZERO cars in the 5* section at 8am, so I picked a Corolla from Gold (Sentra, Elantra, Corolla).

ORD picked from 5*, at the gate I was given some grief about the Surburban I took from the 5* section (Full size sedans, Suburban, Minivans), then once they affirmed it was in the 5* section, told me I was Gold and shouldn't have taken it, and showed my 5* status on my phone and told them I was a National Executive (seeing their reaction was funny).

Can't say the experience or car selection is anywhere close to National.

Since the introduction of Ultimate Choice, I would say that 5 Star is DEFINITELY worth it.

Prior to this year, I was President's Circle member for at least three years, and I thought that status was just meh. So my level dropped to 5 Star at the beginning of this year, but my experiences have been much better with much better car options to choose from with UC. I was getting really nice cars from various airports as 5 Star in the 5 Star section. I have since regained my status as PC, and depending on the airport, the car otpions can be comparable in many regards.

In summary, recently I would argue that 5 Star is definitely worth something with Ultimate Choice.

Assuming you're talking about an ultimate choice location, 5* generally has the same cars as regular gold but with lower mileage and/or higher trim levels.