GGG is the better fighter in my opinion and SHOULD win. But given his limited experience against top comp his chin (while it seems good now) will be a question mark given AA's power. I'd still take Golovkin though and he's better to watch.
I really don't like how a turtle shell defense matches up against GGG's offensive variety, particularly the left hook to the body. Abraham's low workrate and round stealing strategy of waiting until the last minute to fight also does him no favors. I think GGG stops him on body shots by the 10th.
I'd give the edge in boxing ability to GGG. I can see him landing combinations all night and keeping AA on the outside. However, there is always that variable, and that is AA's power..the dude was a murderous puncher, he could easily catch GGG through his defense and put him to sleep. Still, GGG by decision.
With the hype over GGG at the moment and AA having had his weaknesses exposed it seems the the obvious choice would be Golovkin. But has Golovkin beat anyone as good as AA or as dangerous? Golovkin would be facing a fighter who is just as fearsome a puncher and better defensively. Golovkin is pretty easy to hit and would very likely eat some hard shots. AA showed a good chin during his career and with that tight guard isn't always easy to get to, he is just easy to outwork. Golovkin wouldn't be boxing him, he be there to hit so AA won't be outboxed and will have opportunities to land. Not sure who would win. It will come down to who can take the others shots better.
From a one-punch standpoint, Stevens hits extremely hard at 160 and gave us a glimpse at what GGG's capable of against a shorter power puncher with a low workrate who waits for his shots. I'm not saying Stevens at 160=Abraham at 160, but there's enough of a correlation that it's not a complete guess. The punch of the fight, for me, goes back to the left hook to the body that GGG throws as well as anyone in the sport right now. That's the punch that opens up the shell guard, and carries knockout power in its own right. Golovkin also has a stronger history of knockouts in the first half of fights than Abraham did at the weight. Arthur's patience bordered on complacency at times. I don't see Abraham doing enough work to win on points, and I have a tough time seeing him land the knockout after I saw how well GGG handled Stevens' power.
Good point about Golovkins left hook to the body, it's a brutal shot and could very well open AA up to head shots. :good