I haven't been able to find a comparison of speed. I've been using serde_yaml to checkpoint simulation state, but the files are getting large and slow, and I'm wondering if it's worth considering moving to serde_json. I know I could be more efficient with a binary format, but I prefer the human-readability and python-readability of yaml or json. Plus, I like being able to add fields (with default values) without invalidating older files.
I've experimented with cbor and Jason, and both are a significant improvement over yaml in terms of speed, with cbor winning by a factor is two or so. I haven't yet gotten to the point of doing analysis in Python, though.