i use DS3A , and i try to get as close to photographic realism as possible in some character studies, but i do not think that a reasonably low-end rendering system like Poser OR DS3 can hope to  get the same quality of 'realism' as those very high end softwares used on major workstations and more to the point, huge renderfarms.
BUT, both can do a very good job with a combination of HQ textures, shaders and a good light rig.
again, BUT, we have to expect very long render times.
a friend of mine is working on some Disney animation stuff and even with her software and VERY high end workstation, a single frame can take quite a few hours to render out.