Suzhou has a very sophisticated CCTV system at SIP, the industrial and financial zone of the city, and it is one of the first cities to implement face recognition as a pilot program. Basically in every block there are cameras installed. I imagine that I appear in the cameras hundreds of times a day.
Does security improve? Definitely. I can give three examples, two personal ones and one that came out in the news.
Once I had an altercation with a person who stopped his car on the bike path, blocking it almost completely. I tried to pass by one side, but suddenly the person accelerated and almost hit me. The driver got off enraged and did not give me time to exchange words with him because he took me by the neck, he lifted me from my electric motorcycle and threw me to the ground. When he realized that he was a foreigner (he wore glasses, and with them many times he passed as a Chinese) he climbed into the car and left. I went to put one complaint at the police station. They told me to go see the cameras in the area where the incident happened and try to identify the person. Unfortunately, everything happened in a blind spot in the camera, so I could not identify it. But I noticed that the quality of the cameras is excellent, you could read the newspaper of a person walking down the street! At that time I would have wished they had better cameras where the fight occurred (it is the oldest area of SIP, where the cameras are more "obsolete").
A friend had a crash on the road and the other driver escaped. He called the police to report the crash. The police asked him to give information on the time and height of the road in which it occurred. They asked him to raise his hand to identify him with the camera. They reviewed the video and after an hour had already found the fugitive.
For a time there was a series of news of criminals who were found in concerts with tens of thousands of people thanks to facial recognition.
Facial recognition seems excellent to me, because it helps to find criminals quickly if crimes happen on the public highway. I can say that Suzhou, and many cities in China are much safer than the more developed cities of America or Europe. Even from the point of view of women, they are not afraid to walk at two in the morning from the bar to the house, nor do they feel uncomfortable when taking the transport. I can not say the same for my friends who live in Paris or Barcelona.
I have never felt that I lose my privacy. At the end of the day, I am in public, the cameras see the same thing that ordinary people can see. So if I do not do anything in public that can embarrass me in front of other people (like nibbling my nose, urinating on public roads, etc.), I do not care that the big brother is watching me (After all I'm not the most interesting person in the world).