P6 opens up a whole new area of materials, ligting and rendering style. In turn, it can slow down the render time. All of your figures mentioned work very well. Due to all of the new bells and whistles you may have to beef up your system, 2gig RAM and a fast CPU ( video card doesn't help render). Is P6 worth getting, yes. Interface is going to be different and will take some getting used to, same with the material room.

I must remember to remember what it was I had to remember.