It's fractionally slower, true, because of the serialization hit (string to binary). The real juice comes from the GIN index - and if you apply it to specific columns instead of a complete document, you have a rocket ship on read.
> It's fractionally slower, true, because of the serialization hit (string to binary).
And with JSON columns you have to serialize on accesses, which is a lot slower in the read-mostly tests.
Stupid question: isn't that the typical result of indexing? Slower writes for (much) faster lookups?