We just watched episode 7 of Season 4. So far the re-creation of City schools is reasonably accurate (though kids carry sunflower seeds, not pistachios). There's a prison knife-fight in the episode, filmed in the stairwell outside our school cafeteria and inside the cafeteria, which cracks me up. That stairwell is like a prison, with a ridiculous wrought iron cage the kids swing from as they run down the steps. It makes me happy to see Omar Little walking where I work every day.
Also, the kid who copied his math homework from a girl and copied her name at the top too is in my homeroom and first period class. He's a smart-ass. I took his test away and gave him a zero for talking just last week. I didn't know he was in the show.