They are not exactly the same or there wouldn't be a 1.1 version would there? Main difference is the shift to the hybrid carriage which supports one direct and one bowden extruder, there is a long thread covering this: https://forum.e3d-online.com/index.php?threads/bigbox-1-1.1041/
Oooo you can use the whole print area with a Dual on 1.1? If that's true they should update the website.