The corporate versions are only as good as the IT person who sets them up. At my previous job, the local IT people configured Norton well, protecting the systems while also not impacting performance of work related tasks. Then someone up the chain at another location decided to take over and the systems slowed to a crawl.

McAfee at my current place of employment works ok for the most part, but I have had to disable it a few times when it silently would do something to a new program install and cause it to fail.