This is what I meant when I said it doesn't smack you in the mouth. The more you play the more you recognize the improvements. It REALLY became apparent to me playing full 12 min per qtr games. The defense alone in 2k12 blows anything you find in 2k11 away. It's not even slightly comparable from the code to the execution.
Again no plays for the user in the demo. The AI in 2k12 is much much better. Not slightly but much better but again it's not a knock you over the head but once you lock horns with this beast for a few 12 min qtr sim games That is when you can really start to appreciate it.
All the work is in the code. It's under the hood. That stuff takes time. But consider post game, offensive rebounding and fastbreak improvements alone along with the offense and cpu defense and there is no way the gameplay of 2k11 holds up well against 2k12.
To some that is not a huge improvement. But a basketball game with improvements in all those areas in gameplay would have to be better than a game that does those exact things poorly... or not nearly as well. Just my opinion of course.