WATERFOX vs. FIREFOX - Which is faster?

I've heard the pros and cons as to which is faster, but I'd really like to get the facts as to which one actually is (faster). I have Windows 7 Pro using a 64-bit OS.

The trouble is that here are so many factors affecting speed that the browser has no control over. A busy server, ISP or even Internet backbone. These factors happen all the time in a practical situation, so I find it difficult to put any variation in speed down to one sort of browser or the other. I've had fast and slow browsing speeds with both.