Some time ago Punkbuster was used (or was even initially built) for use with Counter-Strike. Considering that punkbuster is no longer used with CStrike, its fair to say that I think the cheaters won that battle. But, more to the point, it was a bit of a hassle because then, you had to have it running in the background before launching into a game. The process has been streamlined a great deal with more recent implmentations and I would agree that it now operates smoothly behind the scenes.
ZigZang