KOPS over AWS EKS or vice versa

The two are largely the same, at the time of writing, the following are the differences I'm aware of between the 2 offerings

EKS:

• Fully managed control plane from AWS - you have no control over the masters
• AWS native authentication IAM authentication with the cluster
• VPC level networking for pods meaning you can use things like security groups at the cluster/pod level

kops:

• Support for more Kubernetes features, such as API server options
• Auto provisioned nodes use the built in kops node_up tool
• More flexibility over Kubernetes versions, EKS only has a few versions available right now

Other significant difference is that EKS is an AWS product so you require an AWS account but kops allows to run Kubernetes in AWS but also in GCE and DigitalOcean.