Security in Macs

Just because I can be a bit geeky about computers (that's what I'm studying after all), I thought I should introduce that side of me onto this blog as well ;-P
I came across an article about security in Mac computers and thought it was interesting. With adverts like this:

One does get the impression that Macs are much more secure than windows - this is not true. Every system (as the article underlines) has security threats.
However as I'm a biased Linux user, I'll just say that IMO there's one aspect of security that open source systems (like Linux or BSD) have over ones with closed code (OS X and Windows) and that's a much faster response to security threats (as the article tells us, Mac developpers are particularly slow, despite advertising security as one of their biggest assets).