I do see a that one use-case might be your scenario where one user loses internet connection and comes back online. But this is just valid in cases where multip

I do see a that one use-case might be your scenario where one user loses internet connection and comes back online. But this is just valid in cases where multiple users work on the same set of data and in those cases one suddenly got a more complex scenario(where one probably would need some kind of notification system, sockets, long-polling etc, to notify one user that another one has made a change). In a case with lots of data modifications and a final step of "SAVE/CANCEL" whats your reason for not just keep the "current offline state" in the viewmodel-store and submit these when the user clicks SAVE?(If the user clicks CANCEL on can just reload the initial state from the REST service). This would perform the same task with lots of complexity removed. But if you have discussed all the possible problems above, whats your strategy for keeping the server/view-models properties in sync? Seems like a lots of work just handling that.