I have a true food allergy dog. Finding a food that works for them can be HARD. If you've found one, I would feed it.
Diamond Naturals works for a lot of dogs really well at a reasonable price point. (By the way, Kirkland is interchangeable -- for grain free, their Nature's Domain is worth looking at as it's made in the same plant, by Diamond, for Costco.
The breed rescue I work with feeds both the DN/Kirkland Chicken and Rice and DN Large Breed Puppy versions. These are grain-in foods. More than half of our foster homes use them for personal dogs too. Lost of adopters stay on Kirkland version. For dogs that don't have allergies, they all seem to do very well on it -- better than anything else at that price point. Better foods exist, but not at this price point. For people who need a reasonably priced, decent food, you won't find more bang for the buck. You can trade up and spend more and get into Victor, Fromm, Annamaet, Champion, etc. options, but in some cases you get a third less food for 75% more money.
Like any large manufacturer, there have been recalls, but there hasn't been a major recall in a long time, so they seem to have fixed the quality issue that led to the problems years ago. Save your bag lot codes until the food is gone (but you should be doing this with nearly every brand anyway).
As for DCM, take a look at the massive DCM thread in the archives of this forum (with a title about the FDA) -- it's the best source of info on this forum about what's not known. The last paper by the researchers that was published was frankly mostly a bunch of questions and speculation without answers, in my opinion--and is discussed in that thread. I think if you need to feed grain free, maybe consider adding some beef heart into the diet or a taurine capsule a few times a week as it's not going to do harm (and most dogs love the taste of beef heart, so even if the extra dietary taurine isn't needed, the dog will be delighted).