for example a prepared surface verses and unprepared surface
In essence, the difference will relate to a different (presumed) friction coefficient which, of course, rarely is quoted in the final documentation.
If you get to the point of very soggy surfaces, it gets a bit more complex .. I recall an OEM report on some takeoff tests for the 748 for soft, deep, mud ... interesting. Would bring tears to the eyes of the 4WD muddies brigade. Still have it tucked away in the archives somewhere.