...I use P5 all the time. The improvements to the directory structure, the material room, and the cloth room make it worthwhile. Firefly freezes sometimes, but I've never had a problem with the P4 render engine. Things that don't work are some animation things, hair, and a few other items. They don't work, and they'll never be fixed in P5. Don't buy P5 for any of these. Some people like the face room. I think it's a good first attempt at something, but it doesn't meet any need I have. It runs best on a real 32 bit operating system (XP or Win 2000). It takes LOTS of memory. So if you have an underpwered machine, pass on it. However, with a gig and a half of memory on fast machine, I'm fairly happy with the result.