As always, there will always be different opinions on such matters.. FreeBSD is in a strange boat, they appear to maintain several repositories.. perforce, cvs and svn.. and possibly git.
http://perforce.freebsd.org/
http://svn.freebsd.org/
http://www.freebsd.org/cgi/cvsweb.cgi/
Personally, I like SVN.. but I don't dislike CVS either.
Is the following useful? or are you just seeking speculation? because.. that's pretty much all you'll find here.
http://en.wikipedia.org/wiki/Compari...ntrol_software