I'll note that I haven't read Ben Mezrich's Bringing Down the House (which was the source material). Nor have I seen the PBS documentary about the team of MIT students who broke the bank in Vegas by using a card counting system. So I was coming in knowing just a little about the true story.
It's obvious that some of the events are highly fictionalized. Nobody is going to suspend their belief enough to buy an MIT senior hiding his winnings in his dorm room instead of depositing them in a bank, for example. There are also numerous anachronisms. And there were details that were obviously changed to keep people from having to know certain things about MIT culture. For example, real MIT students don't talk about their classes by name, but by subject number.
But, nits aside, I enjoyed the movie. The twists in the plot succeeded in surprising me and I was very pleased with the ending. Kevin Spacey was excellent as the professor who mentors the blackjack team. Jim Sturgess was very appealing as the student around whom the plot revolves. I was less crazy about Kate Bosworth as the love interest and several of the characters aren't really developed enough to care much about.
This isn't going to be on anybody's list of ground-breaking films. It's also a bit too long and some of the casino / high roller lifestyle scenes could have been trimmed. But it was interesting and diverting. I'd have been willing to pay weekday movie prices to see it.
Besides, how often do I get to be in an audience that applauds at the site of the Great Dome?