Intriguing question, I thought. I went back to look at highlights, and I would say the 2011. It had more fizz, and was more in doubt to right at the end. While the highlights of the 2015 final show a very good Djokovic, I also remember him holding back a bit, after the first, getting rather cautious, playing more not to lose, which gave Stan more and more confidence to swing away. It was the more surprising outcome, based on odds, of course, but I still thought, shot by shot, the earlier one was a rather better match. Funny, this reminded me of how poor the Fed/Djoker match was a year later at RG. Both seemed to be playing to lose, even though I think Novak ended up winning in straights. But it was an awful match.