This was surprisingly a very good experience for us! my friends and I reserved a car for a 3day trip. When we arrived there were quite a bit of people in line, we waited 20mins and was serviced by an extremely friendly lady.
she told us that our car has a 20min wait and offered a better car for extra 20$ per day and we will be able to have it right away. We accepted and she actually took off 15% off the full bill for us as a courtesy gift, so our full rental ended up even cheaper than before! The wait was shorter than most car rental companies, and we received a better car for cheaper without any wait.
The only recommendation I have is to book through expedia since expedia offers collision dmg waiver insurance which is much cheaper. We paid 14$ per day through expedia when we booked while Avis charges 30$ per day. Other than that I was amazed how smooth my experience went despite the amount of bad reviews I read on this company.