My Amida observations:
The difference defensively with Brimah lately has been his improved positioning which is probably a result of gaining more experience and watching some tape with the coaches. He's always been good at being long and going up to block the ball... now he's doing a much better job of putting himself in a position to affect the shot. If he knows he can't affect the shot, he's positioning himself for the rebound (which I believe has also accounted for his improved rebounding of late).
Not only has Brimah improved his positioning, but his basketball IQ has CERTAINLY improved.
He's shown a great knack of balancing his positioning between staying at home on his man versus sagging off his man and going for a block. In many cases, he is both guarding his man yet still anticipating the shot of a penetrating guard and providing help defense if necessary. If an opposing player sees Brimah in position down low, they're not going to go into the paint and challenge him. They'll dribble out or kick the ball out. Brimah seems to be almost baiting guards into coming into the paint... acting like he's covering his man rather than guarding the hoop. And then... with great anticipation... he comes out of no where from the weak-side with his quickness and length to get the block. This accounted for a majority of his blocks vs Florida and I notice him 'baiting' opponents more and more lately.
Once Amida gets a blindside block or two, the opposing team starts looking for him. Even when he's not in position to block or alter a shot, he's affecting the opposing player's shots because they're wary of him. He makes you uncomfortable and that affects your confidence as a shooter. You saw a lot of bad shots by Florida down the stretch because they LOOKED uncomfortable.
As a result of Brimah's better positioning and improved BBIQ, its allowed him to anticipate shots better which is resulting in fewer fouls. He doesn't have to worry about fouling unless its his own man posting him up (he still has a tendency to drop his arms in these instances). And everyone knows we're a more dangerous team with Amida on the floor.