Here's the ingredient list for the regular premium flakes
Main Ingredients: salmon meal, brewers dried yeast, soy flour. Oat flour, corn gluten meal, shrimp meal, dried plankton, dried spirulina algae, dried kelp, lecithin, vitamin supplements a, d3, b12, biotin, thiamine (source of vitamin b1), natural colloring, ascorobic acid ( source of vitamin c). Dried bacillus subtilis fermentation product, dried bacillus licheniformis fermentation
Salmon meal is the scraps from salmon processing plants - the bones, organs, scales, etc. The next four ingredients are garbage, and the fact that they are all listed in succession like that indicates a high probability that that garbage combines to be the bulk of the fish food. Adding wheat and stuff to food is a necessary evil, but some foods will go to excess with it as a way of cutting costs...at the expense of quality. The next source of protein is 6th on the list. shrimp meal - again, the scraps - heads, legs, shells. Very poor protein sources. Spirulina and kelp are good plant sources.
Based on the ingredients, far from a premium food. The fish liking the food is irrelevant to the quality.
Here's the list for the SUPER premium food
Ingredients: Fish Meal, Wheat Flour, Soy Flour, Shrimp Meal, Brewers Dried Yeast, Krill Meal, Soy Lecithin, Fish Oil, Emulsifier, Choline Chloride, Sorbitol, Propylene Glycol, Artificial Color, Spirulina, Yeast Extract, Calcium Phosphate, Anise Oil, Xanthophyll Pigments, L-Ascorbyl-2- Polyphosphate (source of Vitamin C), Canthaxanthin, Manganese Proteinate, Zinc Proteinate, Copper Proteinate, Calcium Iodate, Iron Proteinate, Cobalt Proteinate, Calcium Carbonate, Sodium Selenite, Vitamin A Acetate, Vitamin D3 Supplement, dl-Alpha Tocopheryl Acetate (Vitamin E Supplement), Vitamin B12 Supplement, Riboflavin Supplement, Niacin, Calcium Pantothenate, Menadione Sodium Bisulfite Complex (source of Vitamin K Activity), Folic Acid, Thiamine Mononitrate, Pyridoxine Hydrochloride, Biotin, Ethoxyquin, TBHQ (preservative).
It's even worse.