WOW! I love reading these questions about food, the passion we express is amazing!

To the OP, I have tried Maddie on several foods. Luckily, she LOVES RC. I know it may not be rated as the "best" by the food rating sites, but it is certainly not the worst. She has shown no sign of allergies to this food. I know many do not like corn products in thier food, but as this is just a filler, which I feel is similar to potato products, fillers.
So far she is doing great on it. I have spent so many hours reading reviews of food it is not even funny. Everywhere I looked, there seemed a better food. Good luck in your food choice.
BTW, a very good freind of mine is a vet. So I asked the question about getting kickbacks. She said she has never heard of that. She carries Science Diet along with other brands. She says Science Diet seems more eager about keeping her office stocked than other brands, but no kickbacks.