I have both but mostly stick to Propack. Poser 5 is stable for me with the patch, but slow. Cloth is complicated, I don't care for the hair, face room is fun but kind of a toy. I'm not that impressed with Firefly and the new materials since I use Bryce which also has scenebuilding tools that Poser sorely lacks. If I avoid the hair I don't have to use Firefly so I just do stuff in ProPack which is faster. Some nice features in 5 though like the libraries and parameters. Sigh. Put those in P4 Propack and I'd never look at P5 again.