After playing 2k11 so much, it was hard to get into this version of the game because its predecessor was so arcade-y, even though it was awesome. This one is more sim-y and is therefore more challenging... at the same time though, it's very rewarding when you pull things off. Plays and getting open looks are very important in 2k12. Don't push your shots/plays and take it cool, and you'll do fine. Don't be afraid to call a time-out when you're getting destroyed, if your teammates aren't defending well, or if momentum is shifting.
There will be moments where you'll be left scratching your head though, like when you miss open threes and the like when there is no one around you. I think part of why this happens mostly has to do with the course of the game, ie. whether you were actually ready to take that three, even if no one is covering you, or even if you pulled the shot off perfectly :/. I've been playing My Player mode mostly, and as my ability in shooting improved, I'm finding myself getting a lot more successful shots when I'm open now.
I'm just kinda bummed that Dominique Wilkins wasn't one of the Legends you can play as in the challenges.
PS: I wasn't a huge follower of basketball before (mostly because my local team sucks :(... and I don't have cable - not many over-the-air games), and after playing 2K11, I learnt a bit more and appreciated the sport better... with 2K12 now.. I'm learning tons more because of the importance of plays (and learning a few of these as well) and getting open. The off-ball offense gameplay is fun for me :).
PPS: Don't even try to play this on your keyboard xD. In 2K11 it was doable, but this year, they streamlined dribbling moves, hop-steps, and spins so much that it's almost a must to play this game with a controller =). Lucky for me I have my Razer Onza =D.