Don't know if it is worth $150 for the upgrade, but it was worth the $109 I paid for it. The only thing I don't like is there is some ugly artifacting in the refraction mode that isn't there in Poser 5. Other than that Poser 6 works like a dream, is a lot more stable, I can render all day with render after render after render without it crashing With Poser 5 ten renders was about the limit before I had to reboot. It loads faster, area render is great, and I like that there are more light types and material room nodes. So far I haven't even encountered the infamous memory bug that a lot of people are having problems with.