I bought a very similar one from Homebase last year, and I think it's an excellent product.
On my light, I'm able to turn off the continuous night light, leaving just the sensor working, which gives off a bright light for about thirty seconds when activated. I find mine useful to light up the landing when going from the bedroom to the bathroom in the night.
It's also good to know that the light also comes on, and stays on, should there be a power cut. I also find it useful to use as a torch when going out into the garden at night, knowing it's always fully charged, giving a good beam every time.