Their Yelp average is atrocious and reading a few reviews made me a little apprehensive. We experienced zero problems, however. I have Avis Preferred Plus thanks to work (not that I've ever rented for work). I booked online and the rate was surprisingly better than anything else I could find. And that's taking into consideration that we were doing a one-way rental to CVG (Cincinnati), so we had to pay for each mile used.
Landing at CLE, I got a notification through the Avis app that I couldn't pick a car but that one would be ready when we arrive. The rental facility is a convenient shuttle ride down the road. We walked straight to the Preferred booth and we were in our car in no time. We ended up with a Kia Soul that was clean and more than adequate for our needs.
Our experience at this Avis was minimal, but that's an indicator of a successful transaction.