All of the suites except Microsoft's have antispam protection; beyond that, they offer slightly different feature sets. The McAfee and Panda products packed in the most security extras, while the Microsoft one had the least (although OneCare does include backup software and disk tune-up tools).
Except for the Aluria and Microsoft products, all of the suites have parental controls where you can block undesirable Web site categories such as sex, drugs, and gambling. Trend Micro's suite offers equivalent URL filtering, though it doesn't call the feature parental controls. While CA's suite doesn't provide its own parental controls, it does include a separate CD that offers the service through BlueCoat's K9 Web Protection. Zone Labs' package supplies Smart Filtering Dynamic Real-Time Rating for categorizing Web sites that aren't currently on a user- or software-defined whitelist or blacklist. The BitDefender, McAfee, and F-Secure suites go the extra mile, permitting parents to specify times when their kids can and can't surf the Web.
The CA, McAfee, Norton, Panda, Trend Micro, and Zone Labs suites offer privacy controls that prevent sensitive data, such as credit card information, from leaving your PC--however, the suites' high-privacy settings are aggressive. For example, the maximum privacy setting in Symantec's suite invoked a high-risk cookie alert every time a site dropped a cookie onto our test system, even when it was from a reputable site such as the New York Times site or PCWorld.com. At the suite's default settings, cookies like these are not considered high risk.
Other cool features: The McAfee, Panda, Symantec, and Zone Labs suites scan several instant-messaging clients for infected attachments. (Microsoft's scans only MSN Messenger.) The Panda, Trend Micro, and Zone Labs packages warn you when interlopers are mooching off your Wi-Fi connection. (McAfee's $80 Wireless Home Network Security Suite also offers protection for your Wi-Fi network.)
While some extra features are handy, others only bulk up a suite's interface. A prime example is Symantec's Norton Protection Center, an additional window that monitors the functions of the suite's components. Adding another icon to your already crowded system tray, it pops up regularly to tell you the status of your security protection. It also presents marketing for other, related products; the Data Recovery portion will show a status of "no coverage" until you buy and install Symantec's $50 SystemWorks utility suite.