Take a look in the Rendo market place, Daz, Poser Pros, Poser World, RDNA, etc. How much of the product offered at these locations are P5 specific? That's right...not much! As I look at the products that are available and continue to be made, the vast majority are still being designed for Poser 4 or Pro-Pack....including all the newest glitzy products being created by DAZ. If I had Poser 4 and was considering an upgrade, I think I'd go the Pro-Pack route first.