my brain says Gus would've won if it weren't for that one moment, that spinning back elbow deep in the 4th. Up until that point, the consensus was Gus being ahead 2-1 and he was winning the 4th...then Jones turns the tide with one strike.
Jones' biggest threat going into that fight was his wrestling. Gus stuffed all but 1 takedown, all while fresh and took Jones down himself. This, plus that it was Gus' first 5-rounder compared to Jones' 7th, makes him likely more confident and thus he's able to commit more to his punches.
Am rooting for Gus, but if you know my post history, I tend to not let bias get into the way of who I think wins or who won after a fight is over (at least not in a long time, and bias as in favoritism).