A couple of weeks back, Robert Warner, of Availity gave a presentation to The Jacksonville Developers User Group titled "Source Control Using CVS, Subversion and AccuRev."
The link to his presentation can be found here.
He also, in one of his subsequent blog entries, addressed the audience's question of the criteria against which he and his company had evaluated the tools. The blog entry is simply titled "Source Control."
His is a great overview of the major features and functionallity of some of the SCM product solutions out there.