Originally posted by Wikipedia
Despite its widespread adoption, it carries a reputation within parts of the computer enthusiast community as slow and inefficient, as well as being difficult to uninstall. Whatever the reasons, there are certainly a wide variety of opinions on the product, with professional reviewers tending to give it good rankings (often describing it as the best in its category), but actual user reviews tend to describe it as poor. See for instance ZDNet's review of Norton AntiVirus 2004, where the editor's rating was "7.8 Very good", but the contribute user rating average was just "4.5 Mediocre" as of July 2005. It is possible that variations between different systems account for this discrepancy. Other reviewers have described the software as "memory hungry" or "system resource hogger", including the UK's PC Plus magazine review of the 2004 edition.