It would be interesting to see how easy it would be to move that backup data from one synology to another such as if you need to upgrade from a DS model to a SA model, do to performance or capacity.
Also as a word of caution Microsoft and Google will throttle connection coming into their data centers, cloud backup providers are given a different set of data connections rules than standard users, so if you intend to place one of these in a datacenter to backup many different client you could hit that limit quite easily.
But it does look clean and easy to use.