Health, but you have to remember a raw /barf diet is only as healthy as how the food was raised.
Demodex for one can go away on a balanced barf diet. Most allergies found in our dogs too.
None, I don't care what you read or are told about manufactured dog foods.
The only reason we are back to using Blue is cost. At $65 a bag its still not cheap but the markets around here got smart and upped their pricing on all the scraps.