Depends on what you want to do, what your price point is, what your personal learning curve is. There isn't a blanket answer of "one is better." Since you mention both c4d and Vue as "auxilliaries" to Poser it SOUNDS like you mean to create a character or scene in Poser then use a more powerful external render engine, plus environmentals (fog, clouds, skies, trees...) If that's so, add, (as a minimum), Bryce and Carrara Studio to the list. The former has been used by many to import and render Poser items in a larger and more complex environment, often a natural environment. It may be finicky to use but there is a ton of support from experienced users. The latter is now neck-and-neck with Vue for ease of importing Poser scenes and is almost as easy to use as Poser itself, but loses out a bit in the natural terrain department. On the other hand, maybe you intend to model FOR Poser -- and that's an entirely different subject.