I have with both. Datadog is about as plug and play as you can get. I did a few days of work with Elastic cloud. My takeaway was:
• If you can’t afford datadog then elastic cloud is pretty cool.
• If you can’t afford datadog but spend big money on other stuff, maybe question your priorities and engineering time involved?
• If you are already super versed in Kibana/Elastic stuff, then you might have a great time. My stack has been more prometheus, influxdb, grafana, etc. I found the Elastic managed saas service very different and complex for my needs.
• Elastic was a lot more engineering effort for the same level of integrations that I observed.
My 10 cents!
you can monitor some critical metrics with cloudwatch and grafana. If your apps are running prometheus exporters you’ll want to use cloudwatch agent for ecs service discovery so prometheus can scrape the tasks as they come up.