Using Poser 5 and being very happy with it (admitedly, I don't use the face room nor the hair room, and I seldom use the setup room or animation palette). I'm not going back to Poser 4 now that SR3 has solved the stability problems. Most of the "issues" I see reported here are from people who use hair room / collision detection and walk designer, or from people who are struggling with the learning curve.