There is really no point to buy a Cyrix. It is true that they run very cool, but why does that really matter? For the same price you could get a Duron 900-950, which will be much, much faster. Or, even get a lower clocked Celeron and still have a better performing chip. Plus, I don't trust the reliability of the Cyrix too much because of past experiences. They may be okay, but when you're dealing with "clone" CPUs, you may get yourself into a world of trouble if everything doesn't work the way it should. I say go for a Duron or Celeron for the same price.
"Trying is the first step towards failure."