I've heard that the man who started dogfoodadvisor is working on a cat site. I haven't tried the kirkland cat food, but I found that our kitties do better on a grain free food. My older kitty - 14 years old - started throwing up every day and was looking thin. I was feeding her just friskies (wet food) at the time. I switched her to Nature's Variety Instinct (dry food) and she still gets a little Friskies as a topper. No more vomiting and she has gained weight nicely. The vet said she was probably starting with IBD but switching primarily grain free stopped it.
So I would recommend a grain free food. Probably any of the brands that are good for our dogs would be good for the kitties as well.