When there's only one recipe, we'd stop seeing logstash installed twice on every server. There would also no longer be a race condition between when elasticsearch is installed and when logstash decides if it's an agent or a server instance.
I think this seems like a bad idea now. Converting from one instance to the other could be unpleasant (e.g. an ELK server that is also sending logs to other elk servers).
When there's only one recipe, we'd stop seeing logstash installed twice on every server. There would also no longer be a race condition between when elasticsearch is installed and when logstash decides if it's an agent or a server instance.