I feed Kirkland Signature foods(chicken & Rice), made by diamond I think, but sold as a store brand for Cosco. From what I understand this is not the same food as the link you provided, and I don't think the food in that link is supposed to be very good. That is not the premium food. The better food is from the better line from diamond. At least that is the way I understand it.
And I do understand this is not the best food available, but it is within my cost considering my 3 dogs size and my family situations. I believe it is the best within my means. I also supplement with meats.
My dogs are doing great, and for Rocket the itching has stopped.
I am sure you will get more informed replys.
I have to travel 1 1/2 hours to get it, but I buy alot. And it costs me about $16.00 for a 40 lbs. bag. But it is not the same food on the link you provided.
My friends husband is going to start picking it up for me once a month so my travel time will not be an issue. (he works in the same city)
I can get the diamond foods listed on your site at my local tractor store, but the ingredients are different from the diamond made "kirkland signature" at cosco.