http://www.apple.com/safari/
Interesting, apparently Internet Explorer is worst in 2 out of 3 examples - who would have guessed that?
Back to Safari, while it's execution speeds are impressive, it's ability to pass the Acid 2 test is even more impressive. The Acid 2 test is a HTML page that shows a smiley face. Opera 9 passes the test, while Firefox 2 does not. Here is a comparison to the Safari browser and Firefox:
Safari:
Firefox:
As you can see, Firefox comes nowhere near passing what Safari can do easily and with considerable speed.
Those are the pro's to Safari, so you're probably wondering "My goodness, Safari sounds like it kicks ass, why don't I get it?" The answer is simple: security. Safari 3.0 is a Beta release. Which means that it is currently in development and that there are many, many bugs. One of those bugs is that it had a zero day exploit found only hours after its public release. This means it will execute malicious code without the user ever knowing - a big no - no in the web browsing and security world. This one flaw is enough for most people to shy away, after all, who wants their precious computer turned into a zombie PC?
Because of the security issues, I recommend holding off on Safari until the final release, and even then, ONLY if Apple fixes the security issues.