With unknown aerodynamic properties. FWIW. Based on the cross-section diagram posted on the Planet X USA site, they’re V-shaped with a standard 19mm brake track – not likely to be the fastest wheels around.
You can get brand new 404+808 (non FC, with aluminum rim) for ~$1600. The 2011 zipps went on sale a couple weeks ago (everywhere). A few weeks ago I got a 404 FC CC for <$800
Like others are saying watch for some used FC, and throw a disc cover on the back. Or get an 808 FC up front and some powertap wheel then throw a disc cover on the back.