If you have Poser 4, stay with it.... If you are only a part-time and occasional user, you are not going to miss anything by not upgrading IMHO:) I never had Poser 4....jumped right into Poser 5. If I could have chosen, I would have gotten Poser 4 because I could have used it with Vue d'Esprit. Right now, if given the chance, I would "upgrade" from Poser 5 to Poser 4....that's right...I'd go backwards if I could get Poser 4 for the upgrade price! What will you miss if you don't upgrade? "Bugs" for one thing :) Aside from that: Poser 5 has the P5 hair studio. If you have all day to fiddle with creating strand after strand of hair then maybe you would find that useful....I don't. Personally, there are a number of transmapped hair products that look a lot better than the P5 hair. Plus you need a computer with more than 512 mb of ram...that's what I have on a pentium IV 1.7gz. It takes forever to render this hair! It may actually be better for making grass or waterfalls than hair :) I don't think the hair looks that great...unless you like "wiry looking hair" :) Not sure the materials room is that much of an improvement over what you already have. The big change is the materials designed for P5....how many products have you seen that rely on those? Nope, me either! Cloth room: That has the most possibilities I guess for those who already know how to make clothing and can master the huge learning curve involved. It should have been a great tool for those who are doing animation, because of the dynamic nature of the cloth. The problem: animation tools in the rest of P5 have a lot of issues...I don't do animations, so I just know what I read. Face room: limited to P5 figures...I believe just Don and Judy. Have you seen a lot of stuff for sale for Don and Judy?? Nope...me either! Plus, you need the "perfect photo" and a lot of patience to make it work. It is more a tool for the person who is making characters than for someone who fiddles with this stuff as a hobby (which is my case and possibly yours??) Firefly renderer. This may be better than the old Poser renderer (which is also included in P5 by the way!), but again, it demands a lot of computing resources if you're going to render shadow maps and the like. If you're going to do professional prints of your stuff, then maybe the rendering engine is really important. For the hobbiest, there is just so much that the human eye can really differentiate in a gallery where size is limited to 1024x768 or smaller. Bottom line: If you're a hobbiest and are not using Poser to make money, stay with Poser 4. As for Poser 6.....they still haven't come out with their SR-3 patch yet! I don't know if we will ever see a "Poser 6"! Keep your eyes on DAZ Studio....that may be the future in this genre. BTW: Ignore the marketing hype...it's just that.