As the author stated, it really depends on what you intend to use it for.
Fast internal scanning isn't free, because now you need pre-indexing, which is more data, and loses the incremental buildability on the encoding end.
Small transfer size and fast (full) decoding is possible with a single binary format, but unfortunately designers keep falling into the trap of adding extra things that make them incompatible with JSON. It's why I wrote https://github.com/kstenerud/bonjson/
As the author stated, it really depends on what you intend to use it for.
Fast internal scanning isn't free, because now you need pre-indexing, which is more data, and loses the incremental buildability on the encoding end.
Small transfer size and fast (full) decoding is possible with a single binary format, but unfortunately designers keep falling into the trap of adding extra things that make them incompatible with JSON. It's why I wrote https://github.com/kstenerud/bonjson/