Personal preference plays a part in selection of the software. Many people dislike Norton for various reasons, many people dislike McAffee, like you do. No software is 100% effective at doing the job, but the big names are quite good at most. Here is someone's opinion and facts to support the results: http://anti-virus-software-review.toptenreviews.com/
One has to balance the usefulness verses the effect it has on the system and then personal feelings. I have used some of the ones listed and felt the system resources required were too high. Others restricted the access so much that the everyday activities were limited too much to make it useful.