It's an inexpensive way to create a SAN with some software to tie stuff together. Assuming your router doesn't already do most of this, I suppose it could be useful for home users. I find the anti-Prism claims to be getting old quickly, and probably dubious in this case considering users with no security knowledge are being encouraged to create a single access point to all of their data. This obviously resonates with…
I think their difference is in their client-side software. All existing solutions (dropbox, etc) are single-folder sync-all-the-files.
This solution is more like NFS, but with extra features (keep files locally, keep revisions) and mapping of Document/Video folders between OSes.