We often have user which are requested to review and approve documents via the webCube. If they use devices with smaller resolution like laptops with 1920x1080, it is alomst impossible to use the client with document descriptors area, two sections for document review mode and the notes section.
Responsive design could also be the first step into making the mobuleCube superfluous.
Within the coming releases we will improve UX/UI for webCube. Beginning with a new responsive landing page based on dashboards and widgets we will also redesign eFile & document views including responsive layouts for dialogs.