I've been using Perforce on 3 different platforms for 5 months now. The concept of clients is a bit wierd compared to cvs and just checking out and editing a file can be a pain compared to cvs, but Perforce is more advanced than cvs.

If your buildmeister knows it or learns it, it's worth using. I don't know how much it costs, but it's definitely more powerful than cvs. And SourceSafe plain sucks. I haven't looked at Subversion and doubt I will since I don't implement version control, I just use whatever we have where I work.