The reality is though is that it's a tradeoff. Your claimed "best product" by it's very design cannot access anything outside of the user sandbox, therefore something that does try to exploit if it does so outside that context your recommendation is completely worthless.
Except an exploit that tries to write outside the user sandbox will not be able to do so without the user entering an admin password to give it privileges. Thus, safe computing will be sufficient protection.
And claiming that Time Machine et:al are different is sheer fanboiism. They're still processes that could be exploited at a different level that have access to escalated privs, hence are attack vectors.
The OS itself is an attack vector. As I said, you can't do anything about vulnerabilities that may exist that you're not aware of. You can do something about those that you are aware of. In this case, you can reduce the vulnerabilities by electing not to install a 3rd party app that has one built in.
Every virus post you're in here spewing nonsense. While there ARE exploits published, the only thing that the published ones have lacked so far is a delivery mechanism. By saying that OSX is uber safe, and there's never been an exploit and you never ever no way no how would ever need additional protection is NOT doing a service to anyone here, unless that service is a false sense of security which you provide well.
I haven't stated any nonsense whatsoever, and the fact that you claim such indicates you haven't read my posts carefully. For example, I have never said OS X is "uber safe" and, in fact, repeatedly state that no OS is immune to malware. OS X malware does exist in the wild, but it can all be avoided by practicing safe computing. I've also never stated that a user would never need additional protection. In the FAQ I clearly state that the current malware environment could change at any time. If a true virus is introduced, apps like Sophos will not provide protection, as they don't know what to look for. This was already proven with the Flashback Trojan, which no antivirus app initially recognized as a threat, while those practicing safe computing were unaffected. If anything, recommending an antivirus app is providing a false sense of security, as many users believe that once they have one installed, they're safe. The truth is malware detection rates in antivirus apps is less than 100%, so practicing safe computing is required, even with a 3rd party antivirus app installed.
While I agree that OSX is more secure than an equivalent Windows box, saying that it's never been exploited I know for a fact is untrue.
Who said OS X has never been exploited? Again, you're not getting that from my posts. As I've stated repeatedly, OS X malware does exist in the wild, even if none are true viruses.
A 0-Day exploit is only a zero day on the day it's found, what most don't realize is that most are in use for months or even years before they are. It's going to be an unexplained trip of an enterprise level product, that has vendor support that can deal with the research necessary to identify and develop a signature that blocks it. You're not going to get that out of your freebie user space product.
When Flashback left antivirus apps scratching their heads and scrambling to come up with a defense for a week or more, Sophos was included in that bunch. Meanwhile, those of us practicing safe computing watched the panic with complete calm, knowing we were fully protected without the need for a 3rd party app.
If you want to put your trust in Sophos or any other 3rd party antivirus app, that's your choice. As a responsible and informed member of this forum whose motivation is to help Mac users and not to promote any software developer, I'll continue to give users the facts about safe computing and will continue to warn them of the fallacy of trusting 3rd party antivirus apps as their only line of defense against malware.