They dont give any extra power, as they suck in warm air from the engine bay, therefore the extra amount of air they suck in is offset by the air being warmer and therefore less dense.
To get a bit more power (probably only 2 or 3 bhp) fit a panel filter in the standard airbox with a good cold airfeed going to it. It wont sound like an induction kit though.
On a 1.2 though, the increase wont be that dramatic and whatever you do it certainly wont be fast. Id just get an induction kit for the noise, as with it being louder it feels faster lol.
See ya
Matt