If you ever need to use Smart Switch to restore your phone's Smart Switch backupped data stored on your PC, be prepared to face a very unpleasant issues:
1. None of the accounts previously set in your phone will be restored and you will lose all account access IDs and Passwords! So, make sure you list those in a safe place before making "factory data reset" of your phone !
2. Home Screen and all your frequently used applications that you moved from the app list to the Home Screen Panels will NOT be restored, so after performing the Restore you will need to do all the app selection/move manually. To make the job easier, particularly if you had several pages ("panels") with frequently used apps organised by type, always make snapshot of these pages before attempting to run Restore!
3. Some of previously downloaded and installed applications, like MS Outlook, Word, My Backup PRO etc will not be restored. If you kept a list of them you would have to download and install them again!
4. Your previouis 3/4G data usage will also not be restored.
5. Maybe some other issues, but the above are ones I identified just after restoring my Galaxy Note 4 phone.