What are the best foods at Petco? I'm looking right now at Merrick, Blue Buffalo, and Castor & Pollux. Feeding one 40 pound moderately active dog. Currently on Acana, he's been on TOTW in the past. He was on Native in the past but it trashed his coat. No known sensitivities. I'd prefer several flavors of the same formula, I like to rotate protein sources. Grain free preferred, but not required. I like a protein % of at least 24%. Suggestions? I'll probably end up trying a bunch of 5 pound bags before committing to something bigger, but I'm interested in y'all's thoughts. Is there a brand I'm missing? Nutro and Natural Balance aren't that good, right?