I liked the standards concept. I hope it returns for 2017.
It was a great way for teams to show off their performance, and the performance streamers were a nice touch.
Projectiles and Defense returned
I liked the many unique robot designs that came out of this year (971 and 3357 had some of the coolest bots I've seen in FRC).
I liked audience selection, it allowed you to have one less defense to anticipate before the match, you already know what it is.
330's performance on Einstein.
The hoping for your opponent to drop the ball wasn't subtly encouraged this year like stacks in 2015.