I mix Darwin's raw with my guys kibble and he seems fine. no runny stool and he's growing quickly. has energy, shiny coat, nothing else that would lead me to think something is wrong. I DO let it soak, so it's not hard kibble and mixed in raw. When it's soaked for a few minutes it's softer kibble and raw so I don't think there's a difference in digestion rate, if that's a legit concern.
Tiger A.K.A Clown Town- 12/19/13