It's true that it is normal for dogs to gulp their food.
I would not be obsessed with the size of the kibble for that reason alone. If dog is eating with vomiting that don't obsess about it.
While I agreed mostly with with ClantyreSheltie said in her post, I disagree that there is still benefits for some foods to be gained that are geared to small breed, large breed, senior/weight management, etc. I agree that to replace with starch and carb is not appropriate, and that's why I choose grain free.
I also have to put out the question as to whether or not dogs are truly carnivore.....Cats, yes!
Here is an interesting take on the whole question about dogs.....
http://www.dogfoodadvisor.com/canine-nutrition/dogs-carnivores-omnivores/
I won't got into a long diatribe about it, but in my view, for some dogs, specific diets geared to their life stage or size is definitely appropriate, as their needs differ for sure. There are tons of threads on this already so I won't go into it again.
Ok, I've babbled enough for now....