I just watched the whole match after getting through a whole work day dodging spoilers. Ouch. I couldn't envisage a more torturous match for die-hard Federer fans: losing with two Championship points after nearly five hours of up-and-down play, and a shank to end it. But, it's impressive he pushed Djokovic this hard. Djokovic is still looking like he's mostly in his prime form.
Between this match and the AO Nadal beatdown, I think Djokovic has a strong case for BOAT. I don't think he'll ever be considered GOAT over Federer (and if Fed had won this match, this discussion would be sealed forever). But, the opponent quality in all of his 16 major wins is insane: Federer (4), Nadal (4), Murray (5), and then three excellent players in Del Potro, Tsonga, and Kevin Anderson once each. At the very least, he's the most mentally tough and clutch player I've seen. He has the
best ELO ranking too, for what that's worth.