Pervasive connectivity is an essential underlying substrate for smart cities, leading municipalities to start programs where Wi-Fi is the fundamental building block to develop public Municipal Wireless Networks. Even though hundreds of cities around the world offer some form of Wi-Fi access, there are no widely available results regarding the network Quality of Service (QoS), user Quality of Experience (QoE), and overall utilization profile. The Municipality of São Paulo operates a free Wi-Fi Internet program in 120 public spaces called digital squares. We collected user connection data, network performance, and service availability for more than 2 years from the 120 squares and undertook experiments with video streaming in five squares. We used this unique large dataset to evaluate the impact of current admission control practices in public Wi-Fi networks on the network QoS, user QoE and service availability, also providing insights into the most common QoS/QoE issues and their causes. We also leveraged the data set to establish and verify a correlation between the number of users access in the network and specific events occurring in the area.