I didn’t like the cartoonish aspect of it. We are using Creating a Masterpiece and really love that she teaches the kids how to really see an object and draw what is there.
She gives an example of a sunflower and shows how most children draw it when they are first starting to draw. Remember the daisy flowers you doodled in second grade? That is the ‘cartoon’ version of a flower. Yes, we can all see that what you drew is a flower, but does it capture what a sunflower actually looks like? No.
I think Mark’s program would be okay for kids just starting out, but you are definitely going to have to move past cartoon figures eventually :). Why not just start them off the right way?