I run both (obviously on different machines) and have never noticed a difference in effectiveness. The regular AV version is designed to run on a single computer and configuration to be totally controlled by the user. The corporate version can be loaded just as flexible as the regular AV or it can have its configuration locked by the administrator. Probably the only advantage in the corporate version will depend on the CD you have to load it from - I have received some from Symantec that in essence did not require a license file and thence never expired but other than that I don't know of a difference - they both use the same auto updaters and virus definition files.