What bollocks. You aren't paying attention when you surf or something is installed. OSX is secure, but it doesn't fliter adverts without a third party app.
I went back to Firefox almost immediately. I don't know where people are getting this idea that Safari is faster, it loads more quickly for me but thats it. It still has miserable tab handling (why doesn't it remember my old browsing session? Why do I keep having new windows open when I click a link even though I've told it to use tabs?).
There is no free download accelerator for Safari, only crap download managers wihch do little more than Safari's own. The final nail in Safari's coffin for me is that it makes flash jerky and unwatchable on my old processor. Firefox plays the same movies fine.
No add ons are installed. Websites just have empty spaces of white, one I frequent has no ads whatsoever but I know it is meant to.