I think Specialized recommends the saddle in the "nose up" position because this puts the target sit area (the last third of the saddle) more or less level. If you tilt it down to where the nose is level, or at least closer to it, your rear might want to slide forward down the ramped sit area, putting more pressure on your hands, wrists, and arms. Of course, some people will find this configuration comfortable and others won't, but that's the intent of the design anyway.