When at the event the people checking in the participants are asked to keep the event manager informed of how many people have checked in. This feature is available on RE Events. If it can be seen in the participant panel it would save some time rather than going back and forth to the event record to check the stats.
We expected that this would be one of the basic fields for Event information and something that users would want to be able to see/update easily in a Constituent record in NXT.