SharePoint Workspace 2010 (No More Groove) provides much more features like taking SharePoint Site content Offline. The content(documents, lists) can be edited offline and synced once connected in Network/SharePoint server.
Shared Folder is just like a open space where documents or files can be stored. It can't be compared with SharePoint Workspace.
If you want to keep single copy and all your devices are always connected, then "Shared Folder" may fit.
Otherwise SharePoint Workspace 2010 is Perfect.
Okay the answer says "no more groove". Does that mean I can forget about groove? It says that Shared Folder may fit. Does it fit over internet? Does it fit if the computer is not only 100% all the time. What can you do with one and not the other and via versa? Why give so many similar choices?