Bullet Physics has been VERY disappointing for me. I'm still using V4 and M4, which means that I have to paint the areas where I want movement in an animation. That not only takes a lot of time, but the parameters for the physics are non-intuitive, and the only motion available is up and down. I've wound up relying on the old Jiggles for Poser script in P11 if I want any wiggle in my women characters.