I have put forth a lot of effort on this topic and tried several things. First off, my male adult Mtn. Cur got the runs on diamond feed as a pup, so I put him on a Diamond manufactured brand called Chicken Soup for the Puppy Lover's Soul...sounds dumb, but it was a great feed. It was fine as puppy feed, but it would get too expensive to feed him that all the time as an adult dog. Main ingredients were turkey and chicken and it had other good stuff like fish and omega 6 and 3 and all the good stuff. Way too expensive as a maintanance feed and really too expensive as a seasonal feed, too, but great as a puppy feed.
I tried Diamond maintenance later on and it still gave my dog the runs, so I just switched to the cheap Pedigree for a while. This is probably an enefficient feed for hunting season, but for some reason it gets a dog to look great. Slick, muscular and healthy. However, if you take them to the field, I think you might not get the performance you want.
I also used Diamond High Performance, which is 24% protein/ 20% fat. This type of diamond feed didn't give my dog the runs, but my dog burnt it up too fast and got real skinny and poor looking. His metabolism was too fast for that feed with that kind of content, I guess.
Now just recently I put him on Purina One Lamb and Rice formula. It has lamb as a main ingredient, and has a 26/16 guaranteed analysis. It is also relatively affordable. So far I like it. I think I will ride this squirrel season out on this feed and see how it works.A treedog can really burn up the woods so it will be a good test.
Now for my new puppy, I am just now getting her switched over to Diamond Puppy because it does not give her the runs. I would feed diamond all the time to my male, too, because it's cheap and has a good label reading, but his system just doesn't mix with it. My pup seems fine on it.