P4 works great with it. I've not had any problems with transparencies, etc. P5 doesn't. Vue looks for a P4 installation and if you don't have it, it won't load the .pz3 file. Also transparencies from P5 don't load correctly (at all). P5 specific materials also won't load. P5 hair won't work. I believe Vue has announced support for P5 coming soon. That will make me very happy. I loved doing all the posing and mats in P4 and rendering in Vue. Now I'm working mostly in P5, and just building the backgrounds in Vue (or Bryce).