If you get the Hampton Bay unit, do yourself a favor and either buy a new antenna for it or at least open it up to make sure the existing one is attached securely to the connector. People have noticed problems with these having weak signal and needing a repeater in the same room for them to work reliably (or two repeaters or one a floor above, etc.). The module opens very easily and it's easy to check or replace the antenna. See here for the instructions I followed: Hampton Bay Zigbee Controller - Intermittent Connectivity - Resolved
Since doing this, I was able to get rid of the repeater I placed as close as possible to the fan (for no purpose other than this) and my RSSI has improved greatly despite the latter. This is a lot easier to do before you install the module, so I thought I'd share what I wish I knew then. 
Also, the next hub firmware (2.1.6?) will have a driver update for these that will handle things better if/when you need to reset and repair them and its DNI changes. Hopefully, I won't need to do that anymore, but if i do, that should help too (after I recreate the device once, so if you happen to get this thing tomorrow I might wait for the new firmware just in case).