Dispositif or Apparatus?

Reading Hardt and Negri's latest book, Commonwealth, I'm questioning about the clear terminology used to name the Foucaultian notion of dispositif.

In the preface of this book (p. X) we have to cope with Gilles Deleuze's understanding of dispositif and here we find the untranslated French word.

I think that this is the better (intellectual and scientific) choice instead of re-nominate Foucault's technical term as "apparatus". The heterogeneous nature of what Foucault intends to be "dispositif" seems to me inconsistent with the absorbing meaning of the English term "apparatus". A different perspective could be traced back to the latin roots of the two words insofar as dispositif derives from the Latin dis-ponere (taht is to arrange, put in order), while apparatus derives from the Latin ad-parare, ad-paratus (that is made ready for). On this ground 'apparatus' recalls much more the ultimative function (to response to an urgency), eclipsing both the concrete act of framing the resulting network and the multifarious elements which concurs to give substance to the created set.

For a very deep investigation on this issue, see the transcript of a talk by Jason Michael Adams on Giorgio Agamben's What is an apparatus. This is the link to the web page

Giorgio Agamben's book can be consulted here