Some promising results with my s2 mk2 if anyone else is having some problems getting mapping right:
Install the software from Native Instruments website to be sure (I don't have the Traktor software on the comp I'm using Cross DJ on). Install both the drivers and the Controller Editor.
The "MIDI mode" shortcut of pressing both shift keys didn't seem to do anything for me and the lights don't like up like they do in Traktor (haven't trued running it in the background) but installing the drivers let me start mapping the controller in Cross DJ.
So far mapping by "recording" each button mostly works except:
** I have to change ON-RANGE from 0 to 1 for some of the buttons to not "double click" and disable themselves
** I had to use the Controller Editor to change the jog wheel to "Note", and then map Combo Jog 1 and 2 as "Bidirectional".
**** IINADJ... just trying to have fun with my controller and SoundCloud