At this time, the only commands that support Metrics Indexes are
mcatalog. My understanding is that
mcatalog is only for getting metadata about the contents of the Metrics Index, whereas
mstats is the only command to query / visualize the data.
There is no great interface/dashboard pre-built in Splunk 7.0.0 for exploring Metrics data. Splunk released this Metrics Explorer app at .conf ( https://splunkbase.splunk.com/app/3726/ ), but it looks rushed and poorly put together in v0.1.2.
I know @sideview put a metrics explorer interface in his app at .conf. I haven't played with it, but you can find it here: https://sideviewapps.com/apps/sideview-utils/
As far as the data coming out, I think you have to assume that the output of
mstats is going to be just like
tstats, i.e., you use
prestats in the same ways. With Metrics indexes, there are no such things as events, or at least that seems to be how Splunk is telling people to think about it.