Ok, I've just finished playing my 1st game of ESPN NBA Basketball and I think I liked NBA 2K3 better. So far the new version has been fairly frustrating. Almost any layup or dunk attempt with anyone close to you has a 50% chance of being blocked and a 50% chance of missing if it doesn't get blocked. Also pretty much anytime I try a dribble move (crossover, spin, fake, etc) I get called for a charge because the guy moves forward as he does the move. They've made it harder to steal the ball (which was probably a good thing). Now it seems like I only get steals by picking off passes instead of being able to take the ball from a guy dribbling. The AI is much better at picking apart your defense and finding the open man and making him cut to the basket (strangely when one of your guys is open he doesn't cut to the basket).
Like I said, this is my 1st impression after 1 game. The gameplay has changed a lot since 2k3. Free throws are a little bit harder because they've added a height meter that you have to wait for while you hold the triggers to aim.