I just installed this package in my 2011 Summit RHR. Be patient, as the combined update process (v 2600, gracenotes, and map updates) took close to two hrs to complete. I also was previously running 2.184
When finished, contrary to what was stated in the installation guide, my iPhone was still paired and my radio presets survived.
Was the update worth purchasing ? The jury is out. There are subtle differences in the nav display, and the maps are definitely updated. For example, here in west LA, the 405 rebuild is now properly displayed. I haven't used POI functions yet, but Navtec is claiming there are "thousands" of updates. I am happy with my 2011, and even happier that it's paid off and running well; and plan to keep it until the release of the WK3...
Radio functionality appears to be about the same, but the screen diameter is still only 5 1/2".