This sounds like a disaster for the target market,
In practice, I just can't believe that this isn't going to be a nightmare to implement and maintain, regardless of what they say.
Particularly considering the target market - people who lack the budget for a $200 standalone NAS box ($300 for a dual bay one with mirrored drives), yet have a network with dozens of underutilized machines. The administrators are probably marginally competent at these shops (if there even is an admin). Think about how they're lacking a really basic feature of any business network (shared storage), yet have enough machines to pull it off with unused space. What sort of site is this? What the hell are they using the computers for? It's either a school (where the life of the systems is considerably lower, since students abuse them and the administrators aren't even marginally competent), or a business that has almost no connection to technology, using computers as POS terminals (like the bakery shop example) just realizing they need to pay more attention (but not money, not even a couple hundred for an easy-to-configure NAS box) to IT, or a company that's dropped the ball on IT bigtime.
And now we expect the underqualified admin to schlep around to every machine (because they probably don't have remote access set up - as I just went over, their network is a regular charlie foxtrot) and set up this distributed storage mess?
Ain't gonna fly. Might work (maybe) on a well-run network, but those all have the money for a real storage system.