Lol I love how you have to be like "YES I know" before posting lol. No judging here.
Lots of dogs and puppies grow on on Purina and are perfect and healthy so I wouldn't fault for you even if you decided to continue using it. Also lots of breeders feed Purina and see good results which is one of the reasons they continue to feed it.
Anywho, I've fed Acana for many years off/on with fab results (same company - Champion). Orijen is a bit "richer" (for lack of a better word?) so SOME dogs tend to get looser or mushier stool while on it. I have to say though I've seen the opposite with Jackson, he's eaten Orijen Senior on occasion (we had a few free sample bags even though he's 6 and not a senior, I preferred the protein/fat ratios on that food) and he had perfectly formed nice little poops.
I guess it's what you're comfortable with/what you can afford/etc. Orijen is a bit overpriced IMO when you can get Acana a bit cheaper and is basically the same food (except a bit less 'complicated' formulas which I actually prefer). I use mostly the Singles line though (duck or pork usually). A puppy may need more protein/fat.
Essentially I think it's a fine food, but you can find other foods for lesser price and the dogs will probably just do just as well on them/if not better. But if cost isn't a factor and you're happy with it and your pup does well on it, it's a good food.