How many people do you want to put in one scene? Over 3-- stick to Poser 4-- I prefer ProPack, slightly more stable. How much ram do you have? At least one Gig is recommended by me. I have 2, it's still ohmygod slow. Operating system, if you have Win98 or ME, forget Poser 5. Bottom line, no matter what Poser version you pick, you will have probs. This is not a stable program and hasn't been for awhile. There are memory leaks in every single version and after a prolonged period of working with it, you're gonna have to reboot if you're doing anything thing complicated in your scene. That with any Poser. Since Poser 5 tends to get very slow-- especially if you let the main Runtime get too large, and you have to use the main runtime for the morphs for Daz's millenium3 models. Yup, even the dog. Ok, since 5 runs slowly, that period when you have to reboot comes much quicker, you get less done in the same amount of time. You'll have a lot more fun in Poser 4. For the record, I use Poser 5 exclusively because of the ability to use multiple RUntimes. It drives me nutz. 3G processor, 2G's memory, still slow. Emily