One thing that worries me for Roger is what happens once Novak starts picking up his serve and reading it. Obviously Roger needs to serve well but I have no reason to believe he won't, given how he's been serving at Wimbledon this year. But in their matches, there always comes that stage where Novak turns into rubber man and starts coming with ludicrous returns on the full stretch that land on the baseline and suddenly it's a 30-30 or deuce game with a lot of pressure on Federer.
On the flipside, I think Djokovic has developed the most underrated first serve/second serve combination on tour, and Roger's return of the Djokovic serve has historically been extremely poor, and that was one of the main differences in last year's final. I don't expect Roger to return much better so that's a problem. It also gives Novak way too many easy put aways on 1-2 punches.
The other huge difference last year was Roger's forehand. In fact, I really have no idea how the match was so competitive given how pedestrian it looked (I guess that's a testament to Federer), especially since the backhand to backhand cross court exchanges will generally go Novak's way. I think at this point, Novak has a better rally forehand and because of his superior movement and defense, when they engage in these cross court exchanges he can still get to these angled forehands Federer hits and take Roger out of position with his own angles from really improbable positions. To escape that pattern, Fed needs to be able to change directions and go up the line, which he struggled with last year, but was doing phenomenally well against Murray. I think Roger will hit his forehand a lot better if his match with Murray is any indicator. He was super sharp.
It'd be interesting to see if he gets pop and depth on his sliced backhands since he doesn't want to go toe-to-toe with Djokovic from the backhand side, especially since Novak overpowers him these days. Good news is Roger's down the line backhand generally is on point against Novak and it's an important shot to keep Djokovic honest.
This is way too close to call. If Federer's forehand and serving are on point, I think he wins this. That level of offensive prowess on grass is unrivaled, provided he actually brings that level of sharpness and cleanliness in his game. But if even one of the serve or the forehand is slightly off, Djokovic takes it.