While I enjoy the MGM Grand Hotel/Resort...I am not a huge fan of the buffet. I have tried 3 times and have been disappointed every time.
My issue is in comparison, the higher price sets an expectation that doesn't deliver. Most people want to feel like they are getting what they pay for and here just doesn't feel that way. The food does not sit for too long and there is a sizable selection.
The MGM group has had deals that included free or cheap buffets and that makes sense....if you're paying for a buffet I would suggest going over to Excalibur.