Hi Sharon, I have a client using EzyCollect, but for payments only. The email experience didn't appeal to them- too many limitations on formatting & recipients.
They email statements & other AR followups from NetSuite, but with links back to the ezyCollect customer portal for customers to view & pay invoices online. This setup seems to work well for them.
Their EC instance was set up a year or two ago, not sure whether things might've changed since then.
Another consideration is visibility across teams. To my knowledge EC comms don't sync back to NetSuite.
Hope that helps!