Have you ever avoided buying a cat food brand and why?

I stopped using Whiskas as its junk food for cats. Iams because of its PETA blacklisted status. Started using Natures Best which had a dramatic change in behaviour with the sulky one (George) and less/no fur shedding with both George and Snaffle. However George has started throwing up perfectly digested cat food! Hes healthy otherwise. Would appreciate tips.