As of right now, I use poser 4 pp, and poser 5. After reading many of the p6 threads, I have decided to hold off on purchasing it until it's a bit more stable. I find that P4 is easier to use mainly due to the fact that it loads much faster and has better response times on my old system.(PII, 416mhz, 300megs ram). But when it comes to the directory structure, p5 can't be beat. Just about everything I have for content is installed to my poser 4, with my P5 pointing to that runtime. I don't render with either one, but when I have to, I find the P5 renderer to be easier to use, and the material nodes can come in handy now and then. I might think differently when I get P6, but for now I stick with my P4pp.