This is a solid project and I’m using it in many different projects for years. The developer team is responsive and care about the quality of the project as well as people’s need. I can not recommend it enough.
Yea, I replaced cJSON with this library last year on one of my personal projects and never looked back. Good library. I came to this thread thinking, "Oh, did someone find something nicer than nlohmann json? Now I'm going to have to take some time to investigate it!" Turns out it's the one I've been using.