This tool is excellent when investigating what is going on in your StreamInsight Streams.  I was looking through the menu items recently and went to

Query => Event Fields

I found that there were a couple of columns not added by default to the event viewer (Reminds me of the fact that the Variables viewer in SSIS hides columns also)

Latency

NewEndTime

EnqueueTime

Here they all are together.

This gives us even more information about what is going on