Currently Studiometry doesn't have a field for "Middle Name". If you have set a Middle Name for a contact in OS X, it is lost when sync'd to Studiometry. It is not clear how many other standard fields in OS X Address Book / Contacts are also missing.
Linking Studiometry contacts to AB / Contacts records is a good idea. But it would be better if Studiometry contacts could store all information that could be defined in OS X without problem - especially if Studiometry records are then shared with other users.