I am in the inverse position: i used JSONB when 9.4 came out. I cant speak for comparative performance, but our 8gb db server has no performance issues at all q

I am in the inverse position: i used JSONB when 9.4 came out. I cant speak for comparative performance, but our 8gb db server has no performance issues at all querying an unindexed jsonb column across many millions of rows. The one "gotcha" with the column type right now is comparing hash values to certain data types can be a bit confusing at times, but simple string comparisons in arrays and hashes is relatively straight forward.