I use it all the time and it is not a task killer like many think. It is pretty complex but to sum things up it essentially bumps up the point(s) at which the system would start killing apps on it's own, which I think is around 32-40MB or so of available RAM. It doesn't just kill a random app but instead kills the ones that are not in use, sitting idle or not needed. Without it, once my available RAM gets down to around 50MB things start to get laggy. I have it set to around 85MB and things are always smooth and fast.