Building more on this topic, I drafted a very basic (and not entirely truthful) use case with DJ types and their actions.
(This diagram serves for discussion puposes only…)
The set of Dj types used (radio, club, mobile and turntablist) show that nowadays there is almost no need for the distincion between mobile and club Dj. As my survey is showing me, the virtual applications (Traktor, Mixxx, etc…) can now perform all of the typical DJ gear stuff that is located within the club booths. Furthermore, when equiped with a suitable MIDI controller, a “mobile” DJ is enhanced to become a club DJ, but virtualizing their gear inside a laptop.
The other two categories are needed, Radio DJs have a small range of tools because they only intend smooth mixes between songs played in air-time. Radicaly different, the turntablist/scratch-dj has the longest vocabulary of gestures/techniques to perform his DJ set.