I use Maxwell and DAZ Studio and have tried to use them together—here is a WIP thread showing some of my experiments towards this goal (warning nudity): http://www.maxwellrender.com/forum/viewtopic.php?f=48&t=38386
In the absence of a dedicated plugin, you have to export the scene in another format and import that into Maxwell Studio—this is really only working in OBJ format (FBX and Collada both have issues, though I’m not sure if this is a Maxwell problem, DAZ problem, or both). The problem here is that OBJ does not seem to keep custom triangle groups—which is most often seen as the ears getting the wrong texturing… so you have to manually reassign the triangle groups in Maxwell Studio (not much fun).
That said, after a few days of playing with it I was able to get respectable results from my tests—but honestly I haven’t bothered for a while since it is too much of a hassle.
My advice is to request the people @ Maxwell to create a plugin for DAZ Studio… I for one would welcome that as well.