I should clear something thing up.

In the Ralphling scene, there was in fact very little light added to the final render from use of ambient materials. I did set them up, but back then (with the IDL in the beta versions) the results were far from satisfactory. I was actually advised not even to bother trying to use ambient materials with IDL.
I'd added a couple of extra Spec only lights to deal with specular that was missing with the IDL anyway - I just put a little diffuse back into those lights that accounts for a good proportion of the glow from the monitors and lit signs. There is, however, still some light from the ambient materials (which surprised me at the time).

Just out of interest, that scene originally took over 6 hours to render. I re-rendered it recently with the final release with SR1 and it took just over an hour (and I significantly ramped up the quality settings)! How things have improved.

 

PoserPro2014(Sr4), Win7 x64, display units set to inches.

                                      www.danielroseartnew.weebly.com