With good tooling unwieldy and harder to read shouldn't be an issue for a transmission format. If you need to read a raw transmission you could have a tool that

With good tooling unwieldy and harder to read shouldn't be an issue for a transmission format. If you need to read a raw transmission you could have a tool that presents it a JSON. I find JSON hard to read though, so it's a personal thing. Verbose might be a real issue because it takes more bytes to send the same message. But then if you care about bytes, I think protobuf is worth considering instead of both JSON and XML.