The best resource to verify if a migration has been successful is reviewing the MFG log.
MFG uses a GroupWise Object API ("Account.Allmessages()") to obtain the total items of a GroupWise Account before doing a migration.
The following parameters are filled in when a user migration has ended:
SkippedMsgCnt, TotalApptCnt, TotalContactCnt, TotalMsgCnt, MovedMsgCnt, etc
When a migration is running, the wizard shows the total number of items to be migrated. This value should match the addition of values TotalMsgCnt plus TotalContactCnt. (TotalMsgCnt + TotalContactCnt=Total Items)