It's a little disheartening to see how much the Xbox version is missing when compared to its Xbox 360 doppelganger, but I suppose that's what you should expect when you pay forty bucks less for a game.
Here's my guarantee to you. Rent this game first and play the hell out of it over the weekend. If you don't find that it's totally derivative of "Hoops 2K6," then go back to the store and buy it. That way nobody gets hurt.