I like Dr. Tim's. I feed "Momentum" during the winter skijor season to my dogs. It is a good food, at the right price. Palatability-wise, even my pickiest eater doesn't have a problem . My dogs readily ate the food, especially after working and building up an appetite.
The price is definitely right! I buy it locally from a distributor (musher) and it is a great deal. Most of my skijor friends and many top mushers now use Dr. Tim's products. I've heard nothing but good things about it.
I often put salmon oil, a bit of chopped liver, or even melted butter on my dogs' food to increase palatability and add calories. My malinois especially loves a bit of melted butter on her kibble- and she burns up the calories in no time!