My assessment what I saw live at the game.
Not as terrible a first half as people are making it out to be. Barca were way better simply because they had much more quality on the field. Buffon was good, Mandzu's holdup and aerial threat were nice. Marchisio looked sluggish at times, but that's okay. Benatia and Barzagli put in a decent show but got owned on Neymar's second goal. Our right flank was getting complete overrun though. Not so sure about the others.
Second half was better. Chiellini and Dybala were great. Szczesny was

Higuain's holdup and passing was good, shooting was rusty. Costa looked menacing but still needs to gel with the rest of the team. Sandro was a machine. Cuadrado was by far the worst player on the pitch in the second half with his atrocious decision making.
Wonderful crowd, the Juve fans were outnumbered, but were far more active and noisy than the Barca crowd.