Useful meaning from each metric

Do we have any detailed documents that explains the practical meaning of each metric from Marvel?
For example, what is the total-refresh-time means? for this metric chart, I;m not understand X-Y axis.
The other one is Merge Rate. in a continus index scenario, high merge rate is good or not?
Any idea?

Unfortunately not yet.

However, I did just do a webinar last Wednesday where I described each chart. It should be posted here: