I was last week in the bike shop of the Stevens owner (W. von Hacht) here in Hamburg (Germany). Jens Schwedler, who is in charge of the cyclo-cross bikes told me that the 2011 bikes will have a shorter top tube and a longer head tupe (and the bottom bracket will be slighly higher). These differences in the geometry was a consequence of sponsoring different teams, which asked for such new geometries.
I'm with Mark on this one. I ride the carbon model and it goes where you want it and handles the bumpy stuff at the same time. Fantastic frame. Stevens was very smart to keep the same geometry for all three of their bikes.