* NetApp have a free CIFS copy tool called XCP that claim to be faster than robocopy - it can maybe help you out.
* the only piece of help i have in hand is a script to copy share permissions and volume sizes from 7-mode to Windows shares and file server quota management (used it when migrated a few dozens shares. not worth touching if only have a few)
* the Filer cannot participate in the DFS-r replication group.
* two days ago i wrote here what i think of DFS - you can have a quick look if you interested: http://community.netapp.com/t5/OnCommand-Storage-Management-Software-Discussions/Disaster-Recovery-Options/m-p/139542/highlight/true#M25464