I've seen it mentioned a few times in this group that the 2-piece design of the GE Allegro has the advantage that destruction of the keypad doesn't prevent an alarm signal from being transmitted. The GE Allegro brochure makes this point too. In theory, this sounds nice, as it avoids the cost of a remote keypad.
But looking at how it is implemented, I'm not sure I follow how it accomplishes this. From what I've read, the main keypanel is powered from an AC transformer, and has the connection point for the hardwired zone. It presumably also contains the RF transceiver that is monitoring the sensors.
On the other hand, the dialer (DTIM) is battery powered, and is monitored for failure by the main keypanel every 60 minutes. I didn't see anything suggesting that the DTIM receives triggers from the alarm sensors.
So it seems the only way this would work as described is if the DTIM is programmed to send an alarm notification within seconds of loosing communication with the main keypanel. That seems highly prone to false alarms.