First of all, the loading screen where you can try out some moves with Arenas by himself seems to be different than once you get in the game. Sure you expect it to be different with defenders but it seems you can't execute even basic layups sometimes.
For instance, you have a breakaway layup situation some times and even PGs who could dunk in real life are trying this weak double clutch layup over the rim, where the ball goes straight up and sometimes comes straight down for an airball. This is whether I'm using square or circle, whether I'm turboing towards the hoop or not.
That is a problem more with big men when there's more defenders in the paint. But it seems early in the game, they give you the dunks but later, they can't make a layup to save their life.
Meanwhile, there is a bank layup animation which seems unstoppable sometimes.
I remember in older versions of Live (this is the first one I'm trying in about 4-5 years), they had scripted momentum where one team goes on a 15-0 run where humans control both teams. It wasn't because one guy was so much better, but the game decided to have runs because "It's in the game" crap.
IOW, no better than NBA Jam.
Same issue with outside jumpers, especially 3-point shots. It often seems lopsided. The older Live games would make the team which is trailing become real hot, to make the games close. But the shots don't seem to be about timing. You see James Posey take these fading, off-balance jumpers including 3-pointers and swish it (BTW, no rolls or bounces on the rim in the ball physics).
So is the shot-making more about skills or more about scripted gameplay?