A new study by market watcher Infonetics Research shows that Cisco has the best overall vendor perception in the NAC market compared to Juniper, Microsoft, Consentry, F5, and McAfee. The number one driver cited by users who plan
to use NAC is to better protect resources from unauthorized users and a desire to limit the impact of threats.
http://certcities.com/editorial/news/story.asp?editorialsid=1228#1