My command was with a capital D
With your lowercase d it outputs the check output processed by CMK. The capital D outputs the actual configuration.
Yes, I used capital D. Fat fingers 
This is also available from vCenter. With 1.6 it was so that this was missing with the default vSphere agent. The only missing information, if you pull all the data from vCenter, is the time difference compared to the monitoring server.
I’ve added only using vCenter but the only objects I get for the hosts are local datastore capacities and the power state for each.
To be clear, if I add the vCenter do I still need to create a host object for each host? If yes, with or without the special agent?
To be honest, what I find the most confusing about all this is that the documentation still refers to 1.x as does most of people’s posts. Since the UI is different in 2.x it makes it hard to translate between the two.