Please take a look at some of the Kubernetes case studies: <a href="https://kubernetes.io/case-studies/" rel="nofollow">https://kubernetes.io/case-studies/</a><p>(Disclosure: I'm executive director of CNCF, which funds the case studies program.)
Yes, we've been running a Kubernetes cluster on AWS, built with kops, for about a year. Very happy with it, but there have been some organizational pains getting everyone on board. Nothing I would fault Kubernetes itself for.
Yes, we're running multiple k8s clusters on AWS. Only a few components are not there yet due to their too snowflaky deployment procedures, but we're getting there. So far everyone likes it and would recommend it.
Yes I did several projects bringing Kubernetes to production. In the cloud a little easier then on-prem. But always a real enabler for everyone working with K8s.