There's little argument that Vietnamese Pho came from North Vietnam. Personally I like Northern Pho a lot. But the state of pho today is what it is, that is, many people around the world know the Southern pho as the de facto Vietnamese pho. Many non-Viet diners actually grew up ...
I found the biggest bowl of pho at Kiem Bo Vietnamese Restaurant in North York Toronto, Canada. It was absolutely the biggest bowl I ever had.