Agreed, we've been trying out Rancher since its early days and we're currently in their beta program, we've really enjoyed using it - hits that sweet spot between power and simplicity. Biggest frustration is the lack of a CLI which is preventing us from being able to proceed to production as we don't want to manually handcrank API calls.

You'll actually be able to use Rancher to manage Kubernetes clusters[0] in the next few weeks, if you want the best of both worlds.

[0] http://rancher.com/introducing-kubernetes-environments-in-ra...