First of all, if you have a 4 Gb XBOX, do NOT buy this game. It will not work properly. It will only work on XBOX's with larger hard drives.
With that being said, if you can play the game, buy it. I found the gameplay to be a little choppy, but overall it was a very satisfying experience. The storyline sucked me in and I was forced to make some tough choices that affected future gameplay. I'm playing through it a second time, trying to make different choices than the first time and seeing how it will affect the game.
Can't wait for the next Walking Dead game!