McAffe is well-respected inside the security community, as far as commercial software goes. Personally, I get just as much protection on my machine by using free software (adaware, spybot s&d, avast, zone alarm, etc). As far as better and worse goes, when it comes to security scanners/real time protection, it pretty much all comes down to the definition files. No av software can record all the threats out there, so it's good to have a mix when possible. They overlap on some things, but when they're combined, they give you a much broader definitions base than you'd get from any single scanner.