NCAA 12 improves on most parts of the game, but still has some "typical" EA bugs at launch.
The AI pass defense is absurd. Especially on the harder difficulties, EA really dropped the ball on this one (PUN INTENDED) WR route running is really bad. AI controlled defenders regularly jump routes as you press the pass button, causing a lot of instant reflex interceptions. This happens with linebackers too, jumping nearly 3 feet straight up and picking off passes over the middle that would never be done in real life. Corners run the long way around receivers and then jump the routes to pick off balls, while your wideouts just watch their route get jumped. The AI receivers never make an effort to protect the routes with their body and even with positional advantage, they get run into without pass interference being called and let their pass get picked.
There is a huge lack of penalties - and the only ones I have seen are holding on the offensive linemen and then encroachment and false start/off-sides.
I mentioned this already, but I really have noticed that AI running and blocking is still just as terrible as before. Once you get past the new tackling, you realize that there still isn't realistic physics when it comes to interaction between non-ballcarrying players. Your lead blocker will just bounce off a tackler and leave you to get smashed.
Road to Glory mode's practice mode is almost unplayable due to the AI defense knowing the plays (esp in the running game) and making it impossible to gain yardage.
This game is probably the best in the series, by far. The tackling and blocking makes a huge difference and really opens up the run. That doesn't fix the AI though, so there are still silly linemen not blocking guys from time to time, and the AI runners usually don't exploit the holes they should.
AI running backs typically don't use jukes or cut moves, and instead just turn and run directions. This kinda looks dumb, it would be good if they changed direction with cut steps and jukes like they would in real life. Should be really easy for EA to put in by now, but they haven't. The tackling is great, add realistic direction changes for runners with the ball and it would be perfect. Now, AI runners bounce past their cutback holes and go the whole way around the line, or get tackled. They don't seem very aware of the gaps and angles in the line. They also run along the endzone line to get away from you instead of just forcing their way in and taking the tackle/touchdown. Should be another easy fix.
There is a glitch with custom playbooks. They disappear during playcall screens, you can't go back, and then your guys line up huddled around the ball at the line, and you have to burn a timeout trying to get them to reset. This is kind of annoying, and happens nearly instantly. I actually can't believe they released it with this bug, esp since they touted having custom playbooks. FAIL so far EA. I will give this game an 8 or maybe an 8.5 once they fix this and other major bugs. Hopefully it doesn't take them long.