I wonder if the distributing of the VPN service across nodes would make it harder to detect that you are using a VPN -- something that is good for people like myself not in the US trying to use a USA-based subscription service, like Netflix USA, or Amazon Video USA. They have gotten more sophisticated at detecting VPNs, even ones that you pay for to get better service.
You are right about questioning the speed issue, but I imagine they would plan for that, somehow distributing your connection across several connections, so that like when you load a file via a torrent network, you get incredible speeds sometimes and huge files travel really fast.
I like the idea behind it. Thanks for bringing it to my attention!