Before you buy ANYTHING like this, check the 'entry delay'. I have seen similar items with entry delays of up to 30 seconds...you have to be kidding me! Someone could break in and slay my whole family in 30 seconds.
The entry delay on this model is 4 seconds. I wish it was 2 seconds, but I'll settle for 4. I had a little trouble getting the battery cover off, but other than that, this thing works great. I arm it before going up to bed at night and disarm it on the way down in the morning (it always chirps when it sees me come down the stairs). I've had no false alarms after using it for about 3-4 weeks. I have no pets, so I can't speak to how it behaves with them.
I am buying another one today to maximize my coverage. There are several security codes to choose from, so I can set up two remotes.