I know this has been idle for a while, but I wanted to add my two cents. I started with Poser 8 and upgraded to Poser 9 a couple years later. After a short stint with the Poser 8 included figures, I got the MIL4 figures and have never looked back. I'm still using Poser 9 exclusively and have gigabytes of V4/M4 content. Once you reach a certain level of financial commitment, it's very difficult to justify incorporating the newer characters when there is no built in "backward compatibility", and you have to convert the content manually, (when it's even possible), or start from scratch. With all of the content available for those characters, I can't ever imagine changing at this time, unless I am gripped with a sudden madness that compels me to learn DaZ and start over.