In my house i have 2 keypads one at final exite route, and 1 outside the bedroom on the landing , Also just fitted remote control setting) but the benefit of that is you can set your self into an area, you dont have to go with just a perimeter alarm, you could have different part sets for example:
Full set - Sets whole system when going out
Part Set 1 - (Dusk) Sets just the windows and doors and omits the passive sensors, so you can walk around.
Part Set 2 - (Dark) Sets all windows and doors and ground floor or area not needed to be accessed at night whilst in and around the bedroom, ie bathroom, hence the 2nd keypad so you dont have to walk through active zones to turn the alarm off.
It works really well, but you must remember to turn the alarm off, i install a passive on the staiars to remind us to turn it off, as the missus was setting it off by forgetting to turn it off via the upstairs keypad.
Possibilities are endless really, its all down to cost.