Since different Poser versions have different settings for what an inch is, I stick with the PNU, which is the unit in the .obj files. Some versions of Poser seem to work at 96 inches per PNU, others at some odd figure that doesn't seem to match anything, metric or Imperial. 100 inches to a PNU is easy enough to work with, and sits somewhere in the middle of the various scales that appear to have been used.