Well the characters look absolutely beautiful when rendered in Poser, which is why I would rather render them there.  I would rather lose a tiny bit of detail on the C5 scene and have the characters come out better.  For an example compare these two images

http://www.renderosity.com/viewed.ez?galleryid=1141183&Start=1&Sectionid=0&filter_genre_id=0&Form.Search=sparrownightmare&Form.Criteria=Author

The above image was rendered in C5 with an imported poser character.

 

http://www.renderosity.com/viewed.ez?galleryid=1177169&Start=1&Sectionid=0&filter_genre_id=0&Form.Search=sparrownightmare&Form.Criteria=Author

The above image was done entirely in P6.  They are the same character, just with different clothing.  They used the same base mesh model, the same textures, the same hair etc..  Look at the quality difference.  This is why I would rather render in P6.