ODFE has a security plugin and supports auditing, RBAC and support for node to node encryption[1][2]. The security plugin is based on Search Guard[3].I have run Elastisearch clusters using both the Elastics Co opensource versions as well as ODFE and have personally found the security plugin of ODFE preferable to Elastic Co's X-pack. ODFE also has some additional features included like PerfAnalyzer and SQL interface. In terms of managing the Open Source Elasticsearch vs ODFE they are pretty much the same. I have not used the managed AWS Elasticsearch offering but I read the blog post and felt it had very little to do with ODFE. There is a good feature comparison matrix here:

https://logz.io/blog/open-distro-for-elasticsearch/

[1] https://opendistro.github.io/for-elasticsearch-docs/docs/sec...

[2] https://opendistro.github.io/for-elasticsearch-docs/docs/sec...

[3] https://search-guard.com/