We went through various configurations/deployments of ES in-house, and eventually outsourced the job. The fickle nature of cluster restarts/upgrades were frustrating along with the unassigned & lost indexes that would often result. Then there were cluster partitions that wouldn't heal without a lot of manual intervention.
The tradeoff in value wasn't worth the time it was requiring, so we outsourced to compose.io -- they've been a good fit price & stability-wise, and feel pretty close to a blackbox for the benefit. If you need a large cluster however, you'll pay handsomely with any of the SaaS providers when last I looked at it. For large quantity work we've moved to AWS Redshift.