I recently upgraded my ZD1106 to a ZD1205 in order to get v9.12 for DFS support and to futureproof myself for Wave 2 AP's.
One unexpected side effect after setting up the ZD1200 is how fast this controller is for day to day admin tasks. With ZD1106, the skeleton of the page would load and then fields would pop on the screen one by one, sometimes taking 15+ seconds for all the information to show up. Now with ZD1200, every page loads instantly, and all the information is present when it loads. Firmware updates also go a lot faster, maybe twice as fast.
Of course, this is not unexpected given the improved hardware specs of ZD1200 vs ZD1100. However, it has been a nice unadvertised benefit of the switch.