I found a pretty major flaw in the Eventbrite integration that renders the integration almost useless.
The issue is that anyone with a transaction associated to their contact record gets synced over. But actual attendees associated with the purchase do not get synced over.
This results in a HUGE gap in revenue, especially in a B2B event like a conference, where transactions could have 5-10+ attendees associated to the one purchase.
All of the attendee information is stored in Eventbrite as individual contact information, so there is nothing stopping the integration from syncing it over into HubSpot except for an API in need of refinement.