[Cattius]

In my opinion, Macs are not under significant threat from malware at the moment, but as this problem is only going to get worse in the future, you are well-advised to get an antivirus. Unfortunately, there is this 'it's OK, I've got a Mac' attitude which Apple contributes to - on their site here, they say:

Doesn't get PC viruses.
Designed with security in mind, Mac OS X isn’t plagued by constant attacks from PC viruses and malware. Likewise, it won’t slow you down with constant security alerts and sweeps. Every Mac is secure right out of the box, so you can safely go about your work — or play — without interruption.

I find this very irritating. First they are implying that Macs are invulnerable, which they are not, and second, they use the term 'PC' to refer to non-Mac computers, which is incorrect as Macs are PCs too

I think the speed of my computer outweighs the possible security gap.

In my experience I've never noticed any slowdown from installing an antivirus app (obviously, there is some resource usage, but not to the point that it becomes noticeable). The only ones that can slow things down are bloated apps like Norton, and even that seems to have sharpened up its act now. Of course, I'm talking about Windows antiviruses, but seeing as Mac ones are generally made by the same companies, there shouldn't be any difference.

[Agent F]

In my opinion, Macs are not under significant threat from malware at the moment, but as this problem is only going to get worse in the future, you are well-advised to get an antivirus. Unfortunately, there is this 'it's OK, I've got a Mac' attitude which Apple contributes to - on their site here, they say:

Doesn't get PC viruses.
Designed with security in mind, Mac OS X isn’t plagued by constant attacks from PC viruses and malware. Likewise, it won’t slow you down with constant security alerts and sweeps. Every Mac is secure right out of the box, so you can safely go about your work — or play — without interruption.

I find this very irritating. First they are implying that Macs are invulnerable, which they are not, and second, they use the term 'PC' to refer to non-Mac computers, which is incorrect as Macs are PCs too

Those Mac commercials annoy me because they improperly use the term "PC". Even then, they are using "PC" in reference as a Windows-based computer. "Mac OSX isn't plagued by constant attacks from PC viruses and malware." Of course, because they are different systems. They are confusing less knowledgeable people by making Mac OSX sound immune to viruses all together. It's a lie both ways. Macs are PCs and OSX isn't immune to all viruses.