Yes, good that Elastic finally is rising the bar on free security.
ReadonlyREST will keep developing in parallel SSL and all the other features, because in ES and in Kibana, ROR and XPack security are not compatible: you either activate the one or the other.
To recap, what you get with ReadonlyREST Free edition that you don’t get with X-pack Free:
You get all this for free and open source licensed with Amazon Open Distro for Elasticsearch https://opendistro.github.io/for-elasticsearch/ (including docker and kubernetes support and a lot more features like alerting)
@tom in my experience, the people I talked to have mixed feelings about Opendistro. On our side, since Opendistro launched, we did lose 3 old contracts to it, but we keep on growing nevertheless.
Another thing none of the competitors have is the custom CSS/JS injection. That is, the ability to tweak the Kibana look and feel without messing with the ephemeral “optimized” files or forking Kibana).