All true, I forgot to add that not only do you have to have the AP support license you have to have all your APs supported across all the controllers as well so controller version should be the same. That being said the 1100 will only go so high and the 1200 can only go so low. I believe that 9.9 is the first overlap between the two model. ZD1100 will only go as high as 9.10, so you have to work within those two firmware version if you want to do this between a ZD1100 and ZD1200.
Thanks for keeping me honest guys.