The majority of machines I see come in to my shop infected with viruses and spyware have McAfee on them. I would avoid McAfee at all costs, and uninstalling it is usally a real pain in the ass. I almost always have to run the McAfee product removal tool to get it to uninstall.
I don't believe a fully updated McAfee is really that bad at protection from Viruses and other threats. However, usually the update server breaks without the user knowing, and it quickly becomes useless due to not being updated.
There are several good alternatives to McAfee, some of them even free. Personally, I use AVG on my machines, and the shop I work for recommend it. It is free for personal use, and gets the job done. There is also Avast!, however when I used that, it broke my 16-bit sub-system on Windows XP upon uninstall. Since, at the time, I was still using some 16-bit programs, this made the machine useless once Avast! was uninstalled, worse than a malware infection, and the only way to fix it was to re-install Avast!, or reformat. Nod32 is also good, but not free, and with the alternatives being just as good it isn't worth paying for, IMO.