Above is a sample P6 render. It seems chalky to me.

Then there are these MAX renders of interiors that look brilliant but the model rendered in P6 looks cartoonish. Here is a sample MAX render taken at random from the galleries.
http://www.renderosity.com/viewed.ez?galleryid=1215664&Start=1&Sectionid=9&filter_genre_id=23&WhatsNew=Yes

I both wonder what I can do to improve my renders and why the different apps make different looking renders. I can't afford any thing like Max or even a cheaper render app. I did buy Hexagon for $2 but I have not tried yet to import a Poser scene. The look I am after is photographic rather than super-real, thus the strong shadows on an interior etc. The film grain is looking mannered now... is there a digital noise equivalent now? JPG artifact? :)

Thank you for the responses so far