Thanks for your feedback, I obviously agree with you, but I'm starting to plan to use PG FTS with Django also in some bigger project. I hope to write another article about it in new future.
Depends on the data right. I've seen good performance on larger tables after using GIN indexing with records that rarely needs to be updated and simple queries.
I'm not a expert in PostgreSQL by any means, but reducing cost and learning something never hurts.