My last product was P5/P6 only, because of the use of displacement. Of my next two products (whenever I get time to finish them UGH!), one I know for sure will be P6 only because of the advanced features and the other may be P5/P6 -- I haven't decided if I'll do a PP version yet. I've always been more concerned with creating the best product I can with whatever tools I have than with getting as many sales as possible. If I can get better results using P6 only features, then I'm fine with the hit my sales will take by eliminating PP support. Of course, I don't really depend on my Poser income for anything, so I'm in a different situation than some fellow merchants.