Interesting. Usually my critique for products like this is something along the lines of "great, but how are you going to access your data from the internet?" Typically the answer to that is you need some sort of tunneling service like ngrok to get around port forwarding, CGNAT, firewalls, etc. I maintain a list of solutions here[0]. The problem with most of these services is that they're targeted at developers and aren't something the average user should have to mess with.
In this case, the PiBox is being offered by KubeSail[1], a company which specializes in services like tunneling (they're already on the list mentioned above). It will be very interesting to see if they can bundle it in such a way that people don't have to worry about how the tunneling works. Extra points if they make it easy for users to buy/use their own domains.