As for me I'm trying to choose between Aegis and arch. I'm looking with very big suspect on subversion - my guts feeling is that subversion is too overengineered. Instead of solving real VC problems we see Apache intergration, WebDAV, binary db backend. At the end from the point of view of end user (i.e. me) it doesn't offer much more then old CVS.
P.S. And, yeah, BitKeeper rocks. But it is too expensive for us.