i had installed an auto watch alarm.
runs off the genuine remote, 6 point (4 doors, boot and bonnet), ultrasonics and keypad.
it has a small delay when activating and deactivating (1-2sec) but i find it good.
has a feature where if someone breaks in and cuts the wires the siren keeps going because it doesnt have to be physically connect to run.
it cost me round the $450 supply and install.
i think its pretty good and it does the job.