Determine which record succeeds/fails using addList

We have created a web service that will add a list of records to NetSuite from our queue on a scheduled basis. The queue is set up to resolve NetSuite's inability to handle concurrent web services sessions.  I'm curious to learn how other have handled verifying which record in the list succeeds or fails.  I understand that NetSuite will return an internalid of each success and an error of each failure.  How do I know which element in the list was successful and which failed?  Doing a search for each record to determine if it successfully posted would be too