Hi,
Having just done one of these - actually performed the DEV and waiting to perform QA soon (though not on HANA) - this process works well. The documented process is thorough, however, you must perform all the steps in the right order and don't leave any out. That order being: hardware migration, upgrade, then Unicode conversion by means of export/import. The SPUMG steps are fairly easy, but make sure you know how to perform an OS/DB migration as you will be creating .TSK files during the export/import phase that might need some hacking. And of course, practice, practice, pratice to tune the process, number of processes being used, table splitting, re-start processes, etc.
Hope that helps,
Regards,
Graham