Jacobs went the distance because Jacobs fought a really great fight and would likely beat any mw except GGG and maybe Canelo. Jacobs chin isn't diamond (see his fight with Pirog) but its better than a lot of people expected. It was still a solid win for GGG, though people will never stop discrediting it because they are so used to seeing him obliterate opponents by the middle rounds, and also many just hate him regardless and are always looking to diminish his success.

I wouldn't call Canelo's post Floyd record padded. He is criticized because he had a very controversial win over Lara and never rematched him. His fight with Chavez was essentially just a Cinco de Mayo money grab, but nonetheless he virtually shut out the bigger man. He does deserve legitimate criticism for fighting Khan instead of defending against GGG. Other than that he had legit wins over Kirkland, Smith, and Cotto (though that fight was at Caneloweight instead of 160).

If its a decisive win either way I think the winner will try to beat Saunders to unify the 4 major mw belts. If they beat Saunders then after that, if its Golovkin, he will probably rematch Jacobs then move up to try and catch a belt at SMW. If its Canelo, he will have the world by the balls as he will be the unified mw champ and boxing's biggest remaining ppv draw. A close fight will probably result in a rematch.