wow.  absolutely incredibly realistic for Poser (in other words, something that doesn't have GI, area lights, or other stuff).  i think the double shadow looks a little weird considering the single light source, but then i use your GenIBL iteratively for all environment ambience.  i guess it's sort of like having GI, but it takes a while.  i try to do at least 3 iterations from a base flat color IBL (as suggested to me by Synthetic.), and on my computer that takes a few hours.

are you doing anything special with the glass or the number of bounces?  i know when i tried to use any of your glass advice, i could see the background through it, but no light got through.  it was the weirdest thing.  i gave up and just made the glass transparent (it wasn't really making a difference anyway).