Well I got it, and I must say it is a good game. I played some games and some dunk contests, and I must say it is a lot more enjoyable for me. My first game was Heat @ Lakers on starter, and it went to double overtime.

Anyways, heres some things I already see in the 5on5 game.
-much harder to score in the post
-players push off their guy on the perimeter to try to get open
-ai uses more freestyle of course
-lots of cool post moves
-players that reach too much will get 'beat', where basically they miss the ball and the ball handler is clear for takeoff
-players that lose their dribble can get tied up by their defender, and lose the ball if they hold it too much
-free throws are different somehow... maybe it's because I haven't played in awhile...
Those are just some things, now back to my game.
P.S. One more thing. Adjusted shots are different. From my experience I make them more, and it's basically no more "instantly let go of the ball". I once went baseline with Kobe, took off for a dunk, adjusted my shot, and Kobe went under the basket and laid in a reverse. Very cool.