Have to say I was delighted Stan won another Slam. His power is suspicious given what i believe to be the scale of doping in tennis but i think he has had this power for a long time, there is not much new about his play over the last 3 years imo that i would put down to obvious doping.
The main difference in Stan since 2013 and Magnus Norman coming on board is his mental strength and focus imo. He made a gradual improvement all through 2013 before winning the AO in Jan 2014. Since 2013 he had gone to 5 sets with djokovic 4 times in a row before the FO final. Stan was 6+/1 to win the final, which was madness given the closeness of their previous meetings, the pressure and expectation on djokovic to complete the career slam and the fact that clay has always been Stan's best and favourite surface (imo).
Add to that the lack of recognition he received after becoming a slam winner in 2014 (the general consensus amongst tennis fans and media is that he only won the AO14 because Rafa was injured - before that match Nadal had won 11/11 matches v Stan, without losing a set, hence the general consensus). I think that affected him for most of 2014 and he was quite píssed about it, that and about Nadal limping around the court in the final and taking away from his slam win). Basically he came into this year's FO final with the experience and know-how of a slam winner, with the hunger and point to prove of somebody who hadn't won one before imo. It really was a terrible match-up for djokovic in the circumstances. Stan had zero pressure on him and nothing to lose. I think he was also v píssed about the bagel djokovic gave him in the last set of their previous 5 setter (AO15) and was highly motivated to cause an upset and wreck djokovic's day.
I have watched tennis every day for over 6 years now and I always thought Wawrinka had the talent and skill to make it to the very top of the game. He has always hit massive shots and played some amazing stuff. He has always had a huge serve too. He was an absolute money making machine before 2013, you just waited for him to do the hard part (go a break up) and serve for a set and he would lose focus, hit double faults, unforced errors, lose the head and hand the set back to his opponent on his own at times. Almost guaranteed every time.
It wasn't so much that he was inconsistent, he was consistent enough until he went ahead and then became inconsistent. That is why i think it is more about improving his concentration levels, focus and mental consistency than anything else. Norman has definitely massively improved his fitness, before he seemed to be carrying too much weight and wasn't able to compete physically with the top guys for more than a set and a half. With this improved fitness his overall game and mental focus/belief/confidence improved as well, initially gradually but he had all of that when he won AO 2014.
I do not see this as a 'transformation' like a djokovic, it is more mental than physical for me and he had a lot of room for physical improvement, wheres djokovic was almost entirely physical going from a guy out of breath after 2 sets v Niemenen in Basel in Nov 2010 to a guy who won 53 or so matches from the next month, beating nadal in 4 finals in a row, 2 of them on clay. Stan's change may well be down to doping but it is not as obvious to me. If you look at the earlier round match v Fed, he was hitting the same shots, bombs painting the lines, and it was the same v rafa in Rome a month earlier. When he really wants to, he can play like that.
Wawrinka hasn't had a consistent year but i think that is more down to being inconsistent in his attitude to certain tournaments. If he really wants to win a tournament he is more than capable of keeping his focus for the entirety and he also has the belief that he can beat all of the top players, something he never had before 2014. His head to head against djok, fed and nadal was abysmal before then but is a lot lot closer since.
But it is great for the game, to see a guy like djokovic, on a 28 match winning streak get outplayed like that and being incapable of doing anything about it. Better than seeing two obvious druggies playing a 6.5 hour marathon where endurance wins the match. That defeat and the manner of it is something that could affect djokovic in big pressure matches for a long, long time, who knows.