What version of ElasticSearch is currently used when creating demo index on https://find.episerver.com/?
Why do you ask? I don't think that the version of ES that is used in the platform should change the way you use the service...
I want to know what capabilities it and not. In this case I wanted to aggregate my facets and found out that it's not called "facets" in ES any longer (but aggregations). However, I found a solution for my problem at: