[dgeb]

I hear you, but I think that this can be solved with the UI instead of a blocking approach. The synchronization status of the app (and even individual records) can be shown without preventing a user's next action. As Alex states in his article, you can also warn users about pending requests when they attempt to leave the page or close the browser.

[mirkules]

I think this is what the author meant. Any desktop mail app does't block on send, why should a web app?