First half was one of the most interesting periods of football I've seen in a long time.
Fiorentina played in their usual way and Juve tried very hard to press them, but it's not easy to press a team as good in possession as Fiorentina - especially when they have an extra man in midfield.
Juve's pressing kept the tempo high, but they never really threatened to win the ball off Fiorentina in dangerous positions because they never fully committed to the press.
The problem was that Marchisio couldn't properly join in without leaving Ilicic or Valero in space behind him. Juve could have used one of the three defenders to close that space, but it would have involved opening a space on one side of Bonucci for Kalinic to run into and that wasn't something Juve wanted to allow given the damage Kalinic has done this season when given the space to go behind a defence.
So, for all the high tempo, interesting play, you ultimately had a half when each team was focused on one weakness in the opposition: Fiorentina wanted to use the extra man in midfield to get Ilicic or Valero free; and Juve wanted to get Pogba and Evra to attack Bernardeschi due to his defensive weakness.
Juve did a far better job of expoiting Fiorentina's weakness as they got several good crosses in from that area (including the equaliser). Fiorentina couldn't protect Bernardeschi without exposing Alonso one on one with Cuadrado on the other flank, so they just left that weakness open.
Second half was different because the tempo couldn't be so high. Juve retreated. That meant Fiorentina had more easy possession in safe areas and looked less like finding space between Juve's lines.
With Juve sitting deeper, Kalinic was less of a danger, so Chiellini or Barzagli was able to step into midfield more often to press Ilicic or Valero and that limited Fiorentina's ability to use their numerical superiority in midfield.
Ultimately, you'd have to say Juve and Allegri handled the game very well because Juve created several decent (if not clear) chances, while Fiorentina never even came close to creating a chance.
Given the tactics Juve chose to deploy in the two halves, it probably would have made more sense for Sturaro to start the game and Khedira to come on later, but it's hard to be overly critical of a coach going for the more experienced, calmer player in an intense match.
If Fiorentina are lacking something for that kind of game, it would be a good regista to play instead of Vecino. Just now Fiorentina have to play a lot of intricate football to work the ball around the pitch. They don't have someone with the ability to play a longer pass to go round or over an opposition's press. Moving the ball quicker might have allowed them to get their wide players one on one with Juve's wide players at times, which is something they never managed. With Juve not being threatened wide and sitting deep enough to prevent being stretched long, it was very hard for Fiorentina to find the space to play through the middle of the pitch.