We moved in the early days. Today, we are fairly advanced with regards to our understanding of the internals of Elasticsearch - data nodes, master nodes, indexing, shards, replication strategy and query performance. In hindsight, it would be fair to say that we have been extremely happy with our choice given our limited understanding of running a production scale Elasticsearch cluster 6 months back. With Amazon Elasticsearch we were able to start small, move fast, learn on the go, and fine-tune our cluster for production workloads without having to understand every single aspect of managing and scaling a production scale Elasticsearch cluster.