Sprinkler Systems Video

Several things:
Sprinklers MUST be installed by a professional and designed for the combustible load.
Sprinklers do not save lives in the room where the fire is - for the head to go off (unlike Hollywood) it has to be SO HOT that a human in the same room as the fire is already dead from the heat/smoke. Note a 165F head does not open instantly when the ceiling temperature reached 165F.
Sprinklers also have attendant maintenance and testing regimens to ensure they function properly; I really doubt any homeowners with sprinklers are even aware of these.