My favorite kibble for both puppy and adult is Orijen Large Breed Puppy.
I agree with the above post. It is usually just the difference between 1 or 2 ingredients. In my opinion, the large breed puppy formula is just a smidge better than the adult formula.
in some cases yes, a company's adult formulas are just as suitable as their large breed pup formulas. in some cases a manufacturers large breed puppy formula is indeed designed better for a large breed pup than their regular formulas (it may be primarily a difference in the Ca levels, but that, imo, is a critical difference in large breed pups). large breed pups have particular needs that small and medium breed pups dont, so i would agree that foods labeled "puppy" are not necessary in that case.
at any rate, an ACD is not a large breed.
i would add that i agree that "senior" formulas are especially gimmicky. in fact, i think in many cases they are the poorest of all choices for seniors, with reduced protein levels, where i think seniors need more of that.