Luis,
Check out "Software Engineering with Microsoft Visual Studio Team System" - this is my favorite book for explaining why Visual Studio Team System was created as an end-to-end, integrated solution and is set apart from the alternatives.
There are several case studies available at
www.microsoft.com/casestudies, search for Visual Studio Team System. I've included some of my favorites:
https://www.microsoft.com/casestudies/casestudy.aspx?casestudyid=201353http://www.microsoft.com/casestudies/casestudy.aspx?casestudyid=201310http://www.microsoft.com/casestudies/casestudy.aspx?casestudyid=201311Brian Keller
Technical Evangelist, Visual Studio Team System