The main thing missing from Che, for me, was a lot of nice, easy plugins to deploy to cloud services. You can run your app in the container very easily, but it would be nice to be able to push to, say, Heroku right from the IDE.
Apparently Red Hat have acquired Codenvy now, so it will be interesting to see if they add some integration for OpenShift (their own repackaged Kubernetes).
I haven't even started with a real test, just reading about it, so sorry for my lack of research, I'm just reading through the features (https://www.eclipse.org/che/features/) and saw the terminal, which is fundamental for us.
As I understand, Codenvy didn't “join” the Eclipse Che effort, Eclipse Che started with code that Codenvy extracted from their proprietary product and open sourced, and most of the Che developers were and are Codenvy (now RedHat) employees.