McAfee's anti virus solution, Internet Security Suite is an average product. The software does an OK job providing base level virus and spyware protection, but then tries to do too much by attempting to provide protection in areas most home PCs don't need. The downside of all the additional functionality is a significantly slower system.
I was recently introduced to McAfee's 8 in 1 Internet Security Suite through a relative who was having trouble with a 1 year old laptop. The issue was that a "spyware" warning was showing up on his computer. So the user acted rationally and went out a Comp USA store who was happy to sell McAfee Internet Security Suite. My relative who had been scared by the warning was more than happy to buy total "8 in 1" security for his lap-top for the small fee of $60. What he was not prepared for was what happened when he installed McAfee. The laptop stopped working all together. In this case it turns out security from AOL, Symantec and McAfee were all running at the same time. This is bad. And the warning was actually Norton providing a warning about behavior from AOL's solution.
Realizing the problem I stripped away the AOL solution and then decided to test Symantec's Norton Internet Security vs McAfee. The two products were more similar than different. At the end of the day however McAfee seemed to perform all functions a bit better. The big problem is that either solution will slow overall system performance dramatically. This was mostly true during my test when accessing the internet... it was way to slow over a broadband connection for my liking. The reason for the degradation in performance is that these suites are trying to perform so many functions everything else is slowed down.
That said it is generally a good idea to protect your system from viruses and spyware. It just seems much simpler to use one of many free solutions that focus specifically on virus and spyware protection. Likewise many such products are rated every bit as secure as solutions from Symantec and McAfee. Examples of such products include AVG, Ad-Aware and even Microsoft has free utilities. I would recommend installing any of these solutions before spending money on an annual subscription to other services.