The keypad beeps on this unit at every key press and it is quite audible such that your location is compromised. This is easily modified (if you are willing to void warranty) by removing the cover (from the inside - 3 screws) and removing the circuit board and unsoldering the pizio speaker by from the circuit board. Took me less than 10 minutes and mine wrorks great and is now silent! LEDs still flash to give visual queues. Great value IMHO.
Pros: Inexspensive, Easy to use, Seems vary reliable
Cons: Keypad beeps but can be modified not to (voids warranty I am sure)
This review was written in the old system and had content requirements that are different than reviews written today.