I would personally choose the CORE formula but I may be biased because I prefer the higher protein grainfree diets. I wanted to add, CORE is only around 34% I think, so it's not super super high. I feed Acana and can't say enough good things about it... I just love it, and it's a food made in Canada (by the same company as Orijen). Oh, also, I know Bailey is pretty small and the Core kibbles are a bit big.
http://www.championpetfoods.com/