The problem with the AC Pro (if it's the model I'm thinking of) is that it is no longer supported by the UniFi controller. You can still use the 5.6 LTS series of the controller with it; however the current 5.10 release will not work with them.
(The hassle of maintaining 2 separate UniFi controllers is the reason why I upgraded my APs to the current line. The older AC Pros that are no longer supported are the square-shaped APs. The current line of AC APs (including the Lite and Edu) are all round/disc-shaped.)