Isn't IOS based on OS X? Maybe it's not an either/or thing. Maybe it's simply re-enabling a few more features in IOS that had to be axed to fit it on a phone with limited battery life. True Full multi-tasking comes to mind. Better support for peripherals & ports, and other such stuff.
I've had it running since yesterday -Unobtrusive -Caught 4 virii (keylogger & trojans)missed by ESET NOD32 in software installers I had downloaded -Took about 40% longer to do a full deep scan than Nod32 -No logs showing that the scans ran when scheduled (only a list of detected problems) -Smart enough to look for virus catalog updates right before scanning -Phones home to MSFT (anonymously) with security data It seems less obtrusive running in the background watching applications & downloads than Norton 2009 did on my old computer. I haven't tried Norton 2010 (and hopefully never will) I found ESET Smart Security 4 to be buggy on Win 7 x64 (dropping the internet connection unless I disabled the firewall mini-driver) Overall, this Windows Security Essentials seems like the best option for me right now. And it's free, which is nice.