Best CM-Product??

System

At the moment I am writing an essay about WCM-System at the University and I am wondering what is the best WCM in the market. Although I know all the White Papers of the big player and also some market researchs of Gartner and merrilyn lynch, there is no chance to state that one system fullfills all requierement to be perfect.
Regarding to Interwoven, what are the main reasons why a decision maker should select this one. If I compare Interwoven to Gauss,Divine or Documentum, I can't find main differences. All of them can be modified(hands on code), so that it works fine. Is there maybe a technology that only owns Interwoven, that makes it better than its competitors?
Does anybody know, where I can find some papers related to this question?(I am just a student, so please don't tell me to visit metagroup and to spend my yearly income in a report)