[fstrthnscnd]

> If your worry is parsing speed

I am not personally worried by perf in either case, but I see your point.

> It would take Internet Object years to develop parsers as performant as that

Well, implementing a JSON parser is arguably difficult, for many reasons, I suppose the main one is the flexibility it provides. I don't know if this would be the case for this format however. TBH, I doesn't seem to add too much to CSV, and perhaps it would be simpler to use CSV with the first line of this format has a hint for the data structure.