I've never owned Poser 4, so I have very little to compare with. However, if I had waited about a month longer I would have purchased the Poser 4/Vue Bundle as I have Vue and really wanted to use the two together. I have a 1.7ghz processor, run Windows XP Pro and have 512 mb of ram. I don't use the hair room.....way tooooo slowwwww....way tooo much work! I suppose if I was creating hair for a living, it would make sense, but..... When I compare it to Bryce 4 and Vue for ease of use.....well....Poser is NOT "drop dead easy to use" :)Renders are slower than they should be (the P4 renderer is actually faster). There's the problem with third party lights, and it's behavior is unpredictable. For example, you never know if it's really going to save your file or just "fake it". I've lost entire creations when the damned .pzz didn't save correctly. I now save a .pz3 and a .pzz....really annoying, as well as a waste of space. And I've upgraded with all the latest patches! The material room is probably the best feature of the entire program. One really good thing about it, is that it has given me a whole new appreciation for the proficiency of Vue and Bryce 4! :) If I were as lucky as you and had P4, I would not spend a dime on P5. Frankly, I can't think of any reason to justify making the switch. The vast majority of product releases are being made for the DAZ products which are designed for Poser 4/Pro-Pack or for original creations. Poser 5 "proprietary" content is not that great and if you look around, there isn't much being created for "P5 content". The only really good content is what you'll find on the CD and created by DNA and other third parties. Poser 5 seems to be a program whose features are not quite good enough or reliable enough to be attractive to professionals, almost too difficult for new users and certainly not anything you would want to try on any computer that does not have substantial power. The idea that you can run this on a 700mhz computer with 256mb of ram is almost laughable, unless you are prepared to turn off everything else while using it, get rid of any eye candy on your desk top and tweak your memory resources and whatever else you'd need to tweak to get it to handle the resource needs of the program! I can't imagine using P5 on a Windows 98 or ME machine! I'm waiting for DAZ studio. If it proves to be fairly reliable, the day they come out with a plug in for Vue....P5 is off my computer.