I am new at this but studying hard. I have the XBee S2, not the PRO version. In X-CTU Modem Configuration - Modem: XBEE there is the option of XB24-B or XB24-ZB. I am trying to find what the difference is. I assume XB24-ZB is just newer more up-to-date?
I see in XB24-B there is "ZNET 2.5 Router/End Device API (version 1347)and in XB24-ZB there is ZIGBEE END DEVICE API (version 29A0).
I have a point to multi-point configuration so I do not think I need a router, just an end-point.
Yes, earlier Digi was actively working on XB24-b i.e. XBee ZNet 2.5 because at that time Zigbee (XB24-ZB ) was not there.
But later when zigbee came, they are only working actively on it and not on ZNET.
For your configuration, only use end device if you want to save power, otherwise go for router because both will perform same job with only difference that router will never go in sleep mode.