EKS may be a different implementation in some components (CNI), and have some set defaults (EBS for PVs, etc), but at it's core it is still a relatively vanilla Kubernetes.

Making a switch to EKS doesn't mean that you are stuck with EKS forever, and can set you up nicely to make the transition to a more complex/customized cluster implementation/deployment (likely still on AWS, think kops) easier if you find it's necessary for your use case in the future.